Is cross about second source of cuts (8)
I believe the answer is:
scissors
'cuts' is the definition.
(scissoring is a kind of cutting)
'is cross about second source' is the wordplay.
'about' indicates an anagram.
'source' says to take the initial letters (source can mean a beginning or origin).
The first letter of 'second' is 's'.
'is'+'cross'='iscross'
'iscross' is an anagram of 'scissor'.
'scissor'+'s'='SCISSORS'
'of' is the link.
(Other definitions for scissors that I've seen before include "Cutting instrument made of two joined blades with handles" , "Cutting implement - outdated high jump" , "Small shears" , "Double-edged implement" , "Tool with two crossed blades" .)