Condition affects talker from time to time (6)
I believe the answer is:
fettle
'condition' is the definition.
(fettle is a kind of condition)
'affects talker from time to time' is the wordplay.
'from time to time' indicates alternate letters (letters removed on a regular basis).
'affects'+'talker'='affectstalker'
The alternate letters of 'affectstalker' are 'FETTLE'.
(Other definitions for fettle that I've seen before include "Condition, trim - sometimes fine" , "Condition or trim, often fine" , "Condition (usually fine)" , "Be in fine . . . . . . to be in excellent form" , "A state of fitness and good health" .)