Party united? Nonsense - riven by tense insecurities! (6)
I believe the answer is:
doubts
'insecurities' is the definition.
Although both the answer and definition are plural nouns, I don't see how one could define the other.
'party united? nonsense riven by tense' is the wordplay.
I cannot quite see how this works, but
'party' could be 'do' (do can informally mean a party) and 'do' is found within the answer.
'united?' could be 'u' (abbreviation) and 'u' is present in the answer.
'tense' could be 't' (grammatical abbreviation) and 't' is located in the answer.
'nonsense' could be 'bs' (bullsh*t) and 'bs' is found in the remaining letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for doubts that I've seen before include "Misgivings" , "Suspicions" , "Has reservations, is uncertain" , "Isn't certain about, has reservations" , "Uncertainties" .)