Study small container (4)
I believe the answer is:
scan
'study' is the definition.
(thesaurus)
'small container' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'container' becomes 'can' (can is a kind of container**).
's'+'can'='SCAN'
(Other definitions for scan that I've seen before include "Conform to a metrical pattern" , "Examine (to transmit)" , "Read electronically" , "Conform to rules of poetic metre" , "Scrutinise; glance over" .)