A tenter worried about a pangolin (8)
I believe the answer is:
anteater
'pangolin' is the definition.
('anteater' can be a synonym of 'pangolin')
'a tenter worried about a' is the wordplay.
'worried' is an anagram indicator.
'about' means one lot of letters goes inside another.
'tenter' anagrammed gives 'nteter'.
'nteter' enclosing 'a' is 'nteater'.
'a'+'nteater'='ANTEATER'
(Other definitions for anteater that I've seen before include "It feeds on termites, etc" , "Feeder on termites" , "individual living off workers" , "One's looking for workers" , "Pangolin, for example" .)