Indication, forgetting line, one may need this? (3)
I believe the answer is:
cue
'one may need this?' is the definition.
The definition suggests a singular noun which matches the answer.
'indication forgetting line' is the wordplay.
'indication' becomes 'clue' (clue is a kind of indication).
'forgetting' is a deletion indicator.
'line' becomes 'l' (used when specifying particular lines from a poem).
'clue' with 'l' taken away is 'CUE'.
Can you help me to learn more?
(Other definitions for cue that I've seen before include "Sign" , "Signal to begin - tapered stick" , "Billiard stick - hint - signal" , "Rod used in billiards" , "Actor's line to remind another" .)