The first male worker is uncompromising (7)
I believe the answer is:
adamant
'uncompromising' is the definition.
(thesaurus)
'the first male worker' is the wordplay.
'the first male' becomes 'adam'.
'worker' becomes 'ant' (worker is a type of ant).
'adam'+'ant'='ADAMANT'
'is' acts as a link.
(Other definitions for adamant that I've seen before include "Hard stone" , "Refusing to budge" , "Unshakable (in an opinion)" , "Data man can be quite unyielding" , "Resolute; diamond (arch.)" .)