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
of the distant or comparatively distant past; "We met once long ago"; "they long ago forsook their nomadic life"; "left for work long ago"; "he has long since given up mountain climbing"; "This name has long since been forgotten"; "lang syne" is Scottish