Some unite there, definitely getting hitched (8)
I believe the answer is:
tethered
'hitched' is the definition.
(tether can mean to attach or hitch)
'some unite there definitely' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'TETHERED' can be found hidden inside 'unite there definitely'.
'getting' is the link.
(Other definitions for tethered that I've seen before include "Tied to something with a rope" , "on a leash" , "Fastened with rope or chain, like animal" , "Restrained with a rope" , "Tied (animals) up" .)