Merriam-Webster's Collegiate® Dictionary, 11th Edition
YET
I. adverb
Etymology: Middle English, from Old English gīet; akin to Old Frisian ieta yet Date: before 12th century
1. in addition ; besides , even 2c , on top of everything else ; no less ,
2. a. up to now ; so far , at this or that time ; so soon as now , continuously up to the present or a specified time ; still , at a future time ; eventually , nevertheless , however ,
II. conjunction
Date: 13th century
but nevertheless ; but