Worry about sailors recruiting in times past (7)
I believe the answer is:
concern
'worry' is the definition.
(synonyms)
'about sailors recruiting in times past' is the wordplay.
'about' becomes 'c' (abbreviation for circa).
'sailors' becomes 'RN' (abbreviation for Royal Navy).
'recruiting' indicates putting letters inside (inserted letters are recruited into the word).
'in times past' becomes 'once' (I've seen this in another clue).
'c'+'rn'='crn'
'crn' placed around 'once' is 'CONCERN'.
(Other definitions for concern that I've seen before include "Cause of anxiety" , "Firm - interest" , "Business organisation" , "Affect; solicitude" , "Business - worry" .)