Philosophy of Upanishad
The word Upanishad is combination of three words:
Upa+Ni+Shad "Upa" means "near"
1)Truth (The Supreme Knowledge)
Thus we get three meanings:
1)The book which (by nearess) leads to True knowledge
Which ever meaning one takes it means one and the same that Upanishads are the Books which deals with Truth or reveals the truth.
"Ni" means "to lead"
"Shad"has three meanings:(derived from root "sat")
2)with prefix "Ni" also means to "sit"
3)with prefix "Ni" also means to "destroy"
2)The book dealing with true knowledge which is obtained by sitting near(The Preceptor)
3)The book which destroys (the ignorance) and (reveals) Truth.