It isn’t commonly a contaminating influence (5)

I believe the answer is:

taint

I believe this clue is a double definition.

'it isn't commonly' is the first definition.
(I've seen this before)

'a contaminating influence' is the second definition.
(I've seen this before)

(Other definitions for taint that I've seen before include "Sully, stain" , "Contaminate, pollute" , "soil" , "Source of infection" , "Stigmatise" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app