Figure the first mate is beset by contradictions (5)
I believe the answer is:
seven
'figure' is the definition.
The answer and definition can be both quantities as well as being singular nouns.
Maybe there's a link between them I don't understand?
'the first mate is beset by contradictions' is the wordplay.
'the first mate' becomes 'eve' (I've seen this before).
'is beset by' means one lot of letters goes inside another ('beset' could historically mean 'cover').
'contradictions' becomes 'sn' (I can't explain this - if you can you should give a lot more credence to this answer).
'eve' placed inside 'sn' is 'SEVEN'.
Can you help me to learn more?
(Other definitions for seven that I've seen before include "So many ages of man (AYLI)" , "Cube root of 343" , "Prime number" , "number of swans aswimming" , "Number of sins, seas or dwarves" .)