Bride somehow has left one married - it's a trap (8)
I believe the answer is:
birdlime
'it's a trap' is the definition.
(I have seen 'sticky trap' mean 'birdlime' so perhaps 'trap' could also mean 'birdlime')
'bride somehow has left one married' is the wordplay.
'somehow' indicates an anagram.
'has' indicates putting letters inside.
'left' becomes 'l' (common abbreviation).
'one' becomes 'i' (Roman numeral).
'married' becomes 'm' (abbreviation, e.g. in genealogy).
'bride' is an anagram of 'birde'.
'l'+'i'+'m'='lim'
'birde' placed around 'lim' is 'BIRDLIME'.
(Another definition for birdlime that I've seen is " Sticky substance set to trap birds".)