Sailor pursues second wife - quite a specimen (4)
I believe the answer is:
swab
'a specimen' is the definition.
(I've seen this before)
'sailor pursues second wife' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'pursues' means one lot of letters go next to another.
'second' becomes 's' (common abbreviation).
'wife' becomes 'w' (abbreviation).
's'+'w'='sw'
'ab' put after 'sw' is 'SWAB'.
'quite' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for swab that I've seen before include "Cleaning implement" , "Small piece of cotton used to cleanse a wound" , "Surgical cleaner" , "Among others, Q-tip" , "Pad used in surgery" .)