It is said that he was given the name Idress إدريس because of his constant درس (studying) of the Book of Allah.

However, some scholars of the past disputed this. Az-Zamakhshari said in “al-Kashaaf”, to say Idrees is derived from the word درس is incorrect. If his name was derived from درس then that would mean this is an Arabic name and as a result this name would be able to have tanween and kasra enter upon the last letter. However, because this is not the case it proves that Idrees is a non-Arabic name.

The same goes for the name Iblees, it is a non-Arabic name and it is not derived from the word إبلاس, nor is Ya’qub from عقب, or Israa’eel from إرسال, etc.

This was the opinion of Zamakhshari as quoted by al-Qurtubi in al-Jaami’.

However it is possible that the name Idrees could mean درس in his original language – and Allah knows best.

*Other facts*

-He was the first to write with a pen

-He was the first to tailor clothes out of cloth; before then people wore clothes made from leather

-He was the first to pick up arms and fight against the enemies of Islam

-He was the first to look into knowledge of the stars and arithmetic

-He was risen to the fourth level of Paradise and was seen by Prophet Muhammad alayhis-salaam during al-Israa wal-Mi’raaj.

Sources:

Al-Jaami lil-Ahkaam Al-Qur’an by Qurtubi
Ma’aalim At-Tanzil by Baghawi