Something prickly ripped clothing horrendously at first (5)
I believe the answer is:
thorn
'something prickly' is the definition.
I can't tell whether this defines the answer.
'ripped clothing horrendously at first' is the wordplay.
'ripped' becomes 'torn' (synonyms).
'clothing' means one lot of letters goes inside another (some letters cover up or clothe others).
'at first' suggests taking the first letters.
The initial letter of 'horrendously' is 'h'.
'torn' placed around 'h' is 'THORN'.
Can you help me to learn more?
(Other definitions for thorn that I've seen before include "Prickly plant" , "Sharp spike on a plant" , "source of discomfort" , "Spine - prickle - Old English runic letter" , "Spiny bush" .)