Sharp objects — require a smaller amount mostly (7)
I believe the answer is:
needles
'sharp objects' is the definition.
'needles' can be an answer for 'objects' (needle is a kind of object). I'm not certain of the 'sharp' bit.
'require a smaller amount mostly' is the wordplay.
'require' becomes 'need' (synonyms).
'a smaller amount' becomes 'less' (I've seen this before).
'mostly' means to remove the last letter (most but not all of the word).
'less' with its final letter removed is 'les'.
'need'+'les'='NEEDLES'
Can you help me to learn more?
(Other definitions for needles that I've seen before include "landmark" , "Winds up" , "nettles" , "Pins and - -" , "Western point of the Isle of Wight" .)