Hold check, primarily on nurse (7)
I believe the answer is:
contend
'hold' is the definition.
(thesaurus)
'check primarily on nurse' is the wordplay.
'primarily' indicates taking the first letters.
'nurse' becomes 'tend' (I've seen this before).
The first letter of 'check' is 'c'.
'c'+'on'+'tend'='CONTEND'
(Other definitions for contend that I've seen before include "Compete, vie" , "Struggle; assert" , "Compete; deal (with)" , "Debate - contest - claim" , "Struggle (with someone)" .)