Longman Dictionary of Contemporary English - yet

~1 adv 1 (in questions or negatives) until now or until a particular time  (Has Edmund arrived yet? | The potatoes aren't quite ready yet.)  (- see just1) 2 as yet an expression meaning until this moment, used in questions and negatives  (We've had no luck as yet. | As yet, there's been no news.) 3 not yet an expression meaning not at the present time, used especially in the answer to questions  ("Are you ready to leave?" "Not just yet.") 4 but or in spite of something  (a simple yet effective system) 5 months/weeks/ages yet used to emphasize how long it will be before something happens or how long a situation will last  ("When's your holiday?" "Oh, not for ages yet.") 6 in the future, in spite of the way that things seem now  (We may win yet. | The plan could yet succeed.) 7 even or still  (yet another reason to be cautious | a yet worse mistake | yet again (=one more time after many others))  (I'm sorry to disturb you yet again.) 8 formal still  (I have yet to hear Ray's version of what happened. (=I still have not heard it))  ( USAGE NOTE: YET FORMALITY Yet often comes either immediately after a negative word or at the end of a clause, but there is a difference of style. In a formal meeting you might hear We do not yet know the answer. In informal conversation you might say I don't know the answer yet (NOT I don't know yet the answer). Yet may also be placed immediately after the verb where a clause follows I don't know yet whether she'll come or not.