Study Russian course, then wait (7)
I believe the answer is:
observe
'study' is the definition.
(study can mean to look at or observe)
'russian course then wait' is the wordplay.
'russian course' becomes 'ob' (Ob River - course can mean the course of a river).
'then' says to put letters next to each other.
'wait' becomes 'serve' (to wait on someone is to serve them).
'ob'+'serve'='OBSERVE'
(Other definitions for observe that I've seen before include "monitor" , "See - keep - remark - maintain - celebrate" , "Notice, watch" , "Watch without intervening" , "Watch carefully" .)