Outspoken gents, say, interrupted by commander contrarily (5)
I believe the answer is:
vocal
'outspoken' is the definition.
(synonyms)
'gents say interrupted by commander contrarily' is the wordplay.
'gents say' becomes 'lav' (I can't explain this - if you can you should give a lot more credence to this answer).
'interrupted by' is an insertion indicator.
'commander' becomes 'CO' (commanding officer).
'contrarily' is a reversal indicator (letters in the opposite or contrary direction).
'lav' going around 'co' is 'lacov'.
'lacov' backwards is 'VOCAL'.
Can you help me to learn more?
(Other definitions for vocal that I've seen before include "Forthright in argument" , "Freely expressing opinions" , "Audible in protest" , "Given to speech, often in protest" , "With lots to say" .)