Helpful hint about container for vegetable (6)
I believe the answer is:
turnip
'for vegetable' is the definition.
(turnip is a kind of vegetable)
'helpful hint about container' is the wordplay.
'helpful hint' becomes 'tip' (piece of advice).
'about' indicates putting letters inside.
'container' becomes 'urn' (urn is a kind of container).
'tip' going around 'urn' is 'TURNIP'.
(Other definitions for turnip that I've seen before include "what you eat?" , "Root vegetable of the mustard family" , "'Root vegetable, yellow or white (6)'" , "Watch" , "Large-rooted vegetable related to the cabbage" .)