Deer with new worker, motionless (8)
I believe the answer is:
stagnant
'motionless' is the definition.
(I've seen this before)
'deer with new worker' is the wordplay.
'deer' becomes 'stag' (stag is a kind of deer).
'with' is a charade indicator (letters next to each other).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'worker' becomes 'ant' (worker is a type of ant).
'stag'+'n'+'ant'='STAGNANT'
(Other definitions for stagnant that I've seen before include "Standing still" , "Motionless deer" , "unmoved" , "Sluggish" , "Still and foul" .)