1. (adverb) used in negative statement to describe a situation that has existed up to this point or up to the present time

• as yet
• heretofore
• hitherto
• thus far
• til now
• until now
• up to now
• yet

2. (adverb) to the degree or extent that

• in so far
• insofar
• to that degree
• to that extent

3. (adverb) used after a superlative

• yet