KINESIS

Set to 2 different clues across 2 published puzzles, most often “Stimulus response” — The New York Times, Wednesday, 9 July 2008.

7 letters

Every clue on record, most used first

Stimulus responseonce
The New York Times — Wednesday, 9 July 2008
Activity of an organism in response to light, e.g.once
The New York Times — Saturday, 8 September 2007