Temporary coach dispatched with one's ranking dropping (9)
I believe the answer is:
transient
'temporary' is the definition.
(similar in meaning)
'coach dispatched with one's ranking dropping' is the wordplay.
I cannot really understand how this works, but
'one's' could be 'ans' ('a' and 'an' can mean 'one') and 'ans' is found within the answer.
This explanation may well be incorrect...
(Other definitions for transient that I've seen before include "gone in a trice!" , "Temporary worker" , "fugitive" , "on the move" , "Lasting little time" .)