Remaining matron male ignored (5)
I believe the answer is:
other
'remaining' is the definition.
(similar in meaning)
'matron male ignored' is the wordplay.
'matron' becomes 'mother'.
'male' becomes 'm' (common abbreviation).
'ignored' indicates named letters should be taken away.
'mother' with 'm' removed is 'OTHER'.
(Other definitions for other that I've seen before include "Different (from those mentioned)" , "Alternative of two" , "Very unusual" , "Different; additional" , "Remaining" .)