The Most Glorious One, The Most Honorable.
Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is Al-Majeed (in Arabic: ٱلْمَجِيدُ) meaning the one who is the most glorious, honorable, dignified, noble, and generous. It is another name which covers several attributes. He is the only one deserving of all praise and honor because He is all-glorious.
From the root m-j-d which has the following classical Arabic connotations: to be glorious, dignified, majestic, noble, honorable, to be lauded, exalted, sublime, to be liberal, bountiful, exceedingly generous.
Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is al-Majeed meaning the all-glorious one. His excellence is unparalleled as it does not resemble anything else. It is unique and alone. To be all-glorious is not a single standalone attribute but the quality of perfection of several attributes together (similar to how we discuss in the name al-Jaleel - The Majestic One). Imam Al-Ghazali writes, "Al-Majid the All-Glorious is one who is noble in essence, beautiful in actions, and bountiful in gifts and in favours."
In the Qur'an it refers to Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ as al-Majeed once and it is beautifully paired with the name al-Hamid ("The Praiseworthy"). After all, the one worthy of praise should be the one whose very essence is excellence.
Qaalooo ata’jabeena min amril laahi rahmatul laahi wa barakaatuhoo ‘alaikum Ahlal Bayt; innahoo Hameedun Majeed
"They said, 'Are you amazed at the decree of Allah? May the mercy of Allah and His blessings be upon you, people of the house. Indeed, He is Praiseworthy and Honorable.'" (Qur'an 11:73)
Now, as a word majeed is used to describe both the Qur'an and the throne as being glorious. It has been perfected and therefore should be viewed with high status and high-ranking. The Qur'an is a glorious book since it serves as guidance for all of humanity. Of His throne it is said, "His throne extends over the heavens and the Earth" (Qur'an 2:255)
Zul ‘Arshil Majeed
"" (Qur'an 85:15)
Qaaaf; wal Qur aanil Majeed
"Qaf. By the honored Qur’an…" (Qur'an 50:1)
From Hadith Literature
Ibn Abi Laila reported: Ka'b b. 'Ujra met me and said: Should I not offer you a present (and added): The Messenger of Allah (ﷺ) came to us and we said: We have learned how to invoke peace upon you; (kindly tell us) how we should bless you. He (the Holy Prophet) said: Say: "O Allah: bless Muhammad and his family as Thou didst bless the family of Ibrahim. Verily Thou art (حَمِيدٌ - hamid) Praiseworthy and (مَجِيدٌ - majeed) Glorious, O Allah." 
The believer benefits in knowing Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is al-Majeed in two ways. The first being in worship, when we recite durood ibrahim in prayer we are calling on the names, al-Hameed and al-Majeed. He is the one worthy of praise because of the name al-Majeed, i.e, the perfection of all attributes.
Allahumma Salli ‘ala Muhammadin wa ‘ala aali Muhammadin, kama sallaita ‘ala Ibrahima wa ‘ala aali Ibrahima innaka Hamidum-Majeed. Allahumma barik ‘ala Muhammadin wa ‘ala aali Muhammadin kama barakta ‘ala Ibrahima wa ‘ala aali Ibrahima innaka Hameedum-Majeed. 
The second way a believer benefits from learning about al-Majeed is by understanding that we should work on perfecting our attributes to raise our rank and increase our essence. To be a well-rounded Muslim means to work on our piety, devotion to Allah, studiousness, affection, kindliness, generosity, etc.