Tense about new jeering remark (5)
I believe the answer is:
taunt
'jeering remark' is the definition.
(I've seen this before)
'tense about new' is the wordplay.
'tense' becomes 'taut' (similar in meaning).
'about' is an insertion indicator.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'taut' going around 'n' is 'TAUNT'.
(Other definitions for taunt that I've seen before include "Jeering remark" , "Gibe" , "Jeer, deride" , "Wounding jibe" , "Goad, provoke" .)