Limit time among former Engineers (7)
I believe the answer is:
extreme
'limit' is the definition.
(thesaurus)
'time among former engineers' is the wordplay.
'time' becomes 't'.
'among' is an insertion indicator.
'former' becomes 'ex'.
'engineers' becomes 'reme' (I've seen this in other clues).
'ex'+'reme'='exreme'
't' going within 'exreme' is 'EXTREME'.
(Other definitions for extreme that I've seen before include "lacking moderation" , "Very serious" , "Very great; not usual" , "Exceptional - maximum - farthest" , "Intense; furthest away" .)