Obsequious, wait with one learner inside (7)
I believe the answer is:
servile
'obsequious' is the definition.
(similar in meaning)
'wait with one learner inside' is the wordplay.
'wait' becomes 'serve' (to wait on someone is to serve them).
'with' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'inside' means one lot of letters goes inside another.
'serve' going around 'i' is 'servie'.
'servie' enclosing 'l' is 'SERVILE'.
(Other definitions for servile that I've seen before include "Fawning; menial" , "Toadying" , "Subservent, obsequious" , "Fawning, slavish" , "Slave-like" .)