Understood new cut (4)
I believe the answer is:
sawn
'cut' is the definition.
(I've seen this before)
'understood new' is the wordplay.
'understood' becomes 'saw' ('see' can be a synonym of 'understand').
'new' becomes 'n'.
'saw'+'n'='SAWN'
(Other definitions for sawn that I've seen before include "went up and down?" , "(Of wood) cut" , "Severed" , "Cut with serrated blade" , "timber must be" .)