Stay upright? (4)

I believe the answer is:

stem

I believe this is a double definition.

'stay' is the first definition.
(thesaurus)

'upright?' is the second definition.
(thesaurus)

(Other definitions for stem that I've seen before include "'Stalk, shank (4)'" , "Dam" , "Main central part as of plant or glass" , "Stop the flow of, check" , "Halt flow" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app