What is synonym for "people who can very quickly think what to say". I mean like funny people who have great timing. Is there one exact word for that ability. Not "smart", "canny", "savvy" or "shrewd". Thank you.
It can be used endearingly, as well as pejoratively, but also in both ways simultaneously (as determined by the context):
(all the examples are googlable)
Yeah, as one of the sentences calls it to attention:
The best "general" term I can think of is...
...but in many contexts (particularly, when the quick/effective reply is funny), plain witty is better.