Crossword Genius

Black ones containing family’s swimwear (6)

Ross

I believe the answer is:

bikini

'swimwear' is the definition.
(I've seen this before)

'black ones containing family's' is the wordplay.
'black' becomes 'b' (as in pencil classifications).
'ones' becomes 'ii' (I can't justify this - if you can you should give a lot more credence to this answer).
'containing' means one lot of letters goes inside another.
'family' becomes 'kin' ('kin' can be a synonym of 'family').
'ii' enclosing 'kin' is 'ikini'.
'b'+'ikini'='BIKINI'

(Other definitions for bikini that I've seen before include "Beach clothing" , "Skimpy bathing costume or Pacific atoll" , "Small two-piece bathing suit" , "Skimpy garment" , "Skimpy two-piece swim wear" .)

I've seen this clue in The Times.
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