One needs it for toast (9)
I believe the answer is:
wineglass
'toast' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'one needs it' is the wordplay.
I cannot really see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'for' acts as a link.
Can you help me to learn more?
(Other definitions for wineglass that I've seen before include "possibly held in this port? The opposite" , "Vessel with bowl and stem" .)