The complete title of the Sutra is, ‘THE GREAT MEANS EXPANSIVE BUDDHA FLOWER ADORNMENT SUTRA.’
The Tripitaka Master Hsuan Hua explains the meaning of the title in the following manner:
The Seven Kinds of Greatness may be employed to describe the meaning of the seven words,

1. Great                        Greatness of Substance
2. Means                      Greatness of Appearance
3. Expansive                Greatness of Function
4. Buddha                    Greatness of Fruit
5. Flower                      Greatness of Cause
6. Adornment              Greatness of Knowledge
7. Sutra                        Greatness of Teaching

Therefore it is said,
Discussed in horizontal terms,
Discussed on the vertical plane;
Discussed in terms of dust-motes,
Discussed on the scale of kshetras.
Anyway it is discussed it has infinite and inexhaustibly many principles.

National Master Ch’ing Liang explains the same,
Opening and disclosing the mysterious and subtle,
Understanding and expanding the mind and its states;
Exhausting the principle and fathoming the nature,
Penetrating the result which includes the cause;
Deep and wide and interfused,
Vast and Great and totally complete,
Surely this must be: The Great Means Expansive Buddha Flower Adornment  Sutra!

Annotation
The Avatamsaka Sutra is limitless, boundless, ineffably perfect, incomparably supreme, and filled with infinite spiritual transformations. The Dharma Realm of the Buddhas is all pervasive, awesome, unsurpassed, and immeasurable. Thus it is Great. It is so Great, it has no borders, no boundaries, no impediments. It is extensive, all-inclusive, and inconceivably vast. The Buddha has realized that Greatness. Hence, the Avatamsaka Sutra is known as the complete body of the Buddha, it is the complete wisdom-life of the World Honored One.
‘Means’ refers to methods, the Dharma Doors.
‘Flower’ represents the fragrant perfected virtue of the Buddha, who is adorned with such perfect merit and virtue. The word ‘Sutra’ is a common name among Sutras and is usually explained as having four meanings,

1. Stringing together: From the beginning until the end, all the words are strung together, all the meanings are completely strung together.
2. Attracting: It acts as a magnet and attracts or gathers in all those with potential to be taught.
3. Permanent: In the past, present, and future, it is unchanging and will not change.
4. Method: All living beings throughout the ten directions and three periods of time should rely on this method to cultivate.

The ultimate wisdom, compassion, and meritorious virtues of the most perfectly Enlightened One is found in this Sutra. It is said,
‘To study Buddhism is to study yourself,
To study yourself is to forget yourself,
To forget yourself is to perceive yourself as all things.’
The Tripitaka Master Hsuan Hua says,
“The principles discussed in the Sutra are designed to correct our faults and bad habits. It is absolutely not the case that the Sutra was Dharma spoken for Bodhisattvas with no relation to us, or that it was Dharma spoken for Arhats with no relevance for us. Don’t think, ‘All I as an ordinary person can do is listen to the Sutra. I could never aspire to the states of a Sage.’ To think that way is to throw yourself away, to separate yourself from the Sages.”

In the realm of the Avatamsaka, the past, present, and future is transcended. The most worthwhile thing to do is to study, memorize, recite, write out, practice, uphold, and unite with the Avatamsaka Sutra because it transcends the tyranny of time. It is said,
‘Nothing is impossible unless one does not want to apply effort.’
There is a story about a teacher who wanted to teach his students to use their potential. He wrote the word ‘CAN’T’ on the blackboard. Then, with one powerful swipe, he wiped away the apostrophe and the letter ‘T’ and left the word ‘CAN’ on the board in order to inspire his students to have the courage to do things.
The word ‘Sutra’ is the common name. The other six words, ‘Great Means Expansive Buddha Flower Adornment’ is the particular name.
The Hsien Shou Teaching is the method used to lecture the Flower Adornment Sutra. The Hsien Shou’s Five Teachings are,

1. The Small Teaching
2. The Initial Teaching
3. The Final Teaching
4. The Sudden Teaching
5. The Perfect Teaching

There are Ten Doors which are discussed and explained in detail in National Master Ch’ing Liang’s Prologue to the Avatamsaka Sutra. There are also the Tripitaka Master Hsuan Hua’s esteemed commentaries on the Prologue and the Sutra. The Ten Doors are National Master Ch’ing Liang’s analysis of the Avatamsaka Sutra. They are,

1.   The Causes and Conditions for the Arisal of the Teaching
2.   The Stores and Teachings in which it is Contained.
3.   The Apportionment of Meanings and Principles.
4.   The Potentials covered by the Teachings.
5.   The Shallowness and depth of the Teaching Substance.
6.   The Pervasiveness and Uniqueness of the Purport and Aim.
7.   Classifications by Category, Chapter, and Assembly.
8.   Responses and Insights in Transmission and Translation.
9.   A General Explanation of the Sutra’s Title.
10.  Detailed Elucidation of the Meaning of the text.

All the World Honored Ones come into the world for the sake of expounding the Flower Adornment Sutra. Thus, the Buddha, upon realizing ultimate perfect enlightenment, immediately spoke the Avatamsaka Sutra. The World Honored One is completely replete with all merit and virtue. Hence, the Buddha wishes that all living beings will also eventually become ‘Thus.’ A Great Sage does not appear without a Great Reason.
Before I proceed to make an outline of the Sutra, I must assert that whatever is expressed in speech or writing is not considered as an ultimate Truth. This attempt to introduce the chapters in  the Flower Adornment Sutra, cannot be compared to the analogy of using the finger to point at the moon. Why? Because the finger which points to the moon is a finger of an enlightened Being. The finger is analogous to the Teaching of the Sages. By following the direction of the finger, one can see the moon, that is, arrive at Ultimate Reality. However, Since I am not enlightened, all my words are false (in the realm of relativity). For instance, if the Buddha says,
‘The Tathagata has come and yet not come, gone and yet not gone.’

That is true, real and actual speech because the Buddha has realized the truth of that sentence. But, if I say,
‘The Tathagata has come and yet not come, gone and yet not gone.’
That would be false because I have not realized that Truth. The words are the same. But, when the Buddha says it, it is true. When an ordinary mortal says it, it is false. The Venerable Bodhidharma says,
‘Even if you can explain thousands of Sutras and Shastras, unless you see your own nature, yours is the teaching of a mortal, not a Buddha.’
Why then, make an attempt to delineate the Sutra? Because I believe what all Buddhas and the Great Bodhisattvas say. For that reason, I must still try to convey and perpetuate what is True.

In chapter thirty-nine of the Avatamsaka Sutra, Universal Worthy Bodhisattva says,

For that reason you should listen to the Buddhas’ meritorious qualities.

 The Tripitaka Master Hsuan Hua says,

From the beginning to the end
 of the Flower Adornment Sutra,
 every phrase of the Sutra
 is an Unsurpassed Dharma Jewel.
If we are able to actually Apply and Cultivate
 according to the principles in the Sutra,
 then we are certain to become Buddhas.

The Buddha did not expound the Avatamsaka Sutra so that living beings can embark on an intellectual quest. He spoke it so that all living beings and Sages can understand and strive to embody its ineffably wonderful and boundless principles.