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"
used after a superlative; "this is the best so far"; "the largest drug bust yet"
a time period usually extending from Friday night through Sunday; more loosely defined as any period of successive days including one and only one Sunday
the warmest season of the year; in the northern hemisphere it extends from the summer solstice to the autumnal equinox; "they spent a lazy summer at the shore"