Noticed it was cutting edge (3)
I believe the answer is:
saw
This could be a double definition.
'noticed' is the first definition.
(I've seen this in another clue)
'it was cutting edge' is the second definition.
The definition suggests a singular noun which matches the answer.
Can you help me to learn more?
(Other definitions for saw that I've seen before include "Old saying - cutting kind" , "Viewed; adage" , "Observed the old saying?" , "Noticed - tool" , "Observed; tool" .)