Cutting tool used to be returned (3)
I believe the answer is:
Here is my best explanation:
'cutting tool' is the definition.
(I've seen this before)
'used to be returned' is the subsidiary indication.
'used to be' becomes 'was' (I've seen this before).
'returned' is a reversal indicator.
'was' in reverse letter order is 'saw'.
(Other definitions for saw that I've seen before include "Saying; cut wood", "Old saying for woodcutter", "Noticed - tool", "Noticed; cutter", "Cutting blade", "Old saying for wood cutter", "Implement for cutting wood", "Pithy saying", "Perceived visually" and "Toothed blade".)