Everybody hastened out of the plant (7)
I believe the answer is:
shallot
'the plant' is the definition.
The answer is an example.
'everybody hastened out' is the wordplay.
'everybody' becomes 'all' (I've seen this before).
'hastened' becomes 'shot' (shooting is a kind of hastening**).
'out' indicates putting letters inside.
'all' put within 'shot' is 'SHALLOT'.
'of' acts as a link.
(Other definitions for shallot that I've seen before include "found in the allotment" , "Type of onion" , "One may get into a stew" , "It resembles an onion" , "Species of onion" .)