Definition of yet:
up to the present time; "I have yet to see the results"; "details are yet to be worked out"
used in negative statement to describe a situation that has existed up to this point or up to the present time; "So far he hasn't called"; "the sun isn't up yet"
to a greater degree or extent; used with comparisons; "looked sick and felt even worse"; "an even (or still) more interesting problem"; "still another problem must be solved"; "a yet sadder tale"
within an indefinite time or at an unspecified future time; "he longed for the flowers that were yet to show themselves"; "sooner or later you will have to face the facts"; "in time they came to accept the harsh reality"
used after a superlative; "this is the best so far"; "the largest drug bust yet"
despite anything to the contrary (usually following a concession); "although I'm a little afraid, however I'd like to try it"; "while we disliked each other, nevertheless we agreed"; "he was a stern yet fair master"; "granted that it is dangerous, all the same I still want to go"