Dodgy meal in time causes illness (7)
I believe the answer is:
ailment
'illness' is the definition.
(an ailment is an illness or health problem)
'dodgy meal in time' is the wordplay.
'dodgy' indicates anagramming the letters (a dodgy or wrong order of the letters).
'time' becomes 't' (abbreviation).
'meal'+'in'='mealin'
'mealin' is an anagram of 'ailmen'.
'ailmen'+'t'='AILMENT'
'causes' acts as a link.
(Other definitions for ailment that I've seen before include "I lament (anag.)" , "Malady" , "Slight but persistent illness" , "Bodily disorder or disease" , "problem" .)