Suppose worker is pregnant (9)
I believe the answer is:
expectant
'pregnant' is the definition.
('expectant' can be similar in meaning to 'pregnant')
'suppose worker' is the wordplay.
'suppose' becomes 'expect' (I've seen this before).
'worker' becomes 'ant' (worker is a type of ant).
'expect'+'ant'='EXPECTANT'
'is' acts as a link.
(Other definitions for expectant that I've seen before include "Eagerly awaiting" , "Agog" , "Anticipating" , "Eager to see what happens" , "Pregnant" .)