Attempt to get Eliot back for assignation (5)
I believe the answer is:
tryst
'assignation' is the definition.
(synonyms)
'attempt to get eliot back' is the wordplay.
'attempt' becomes 'try' (synonyms).
'to get' says to put letters next to each other.
'eliot' becomes 'ts' (TS Eliot).
'back' says the letters should be written in reverse.
'ts' reversed gives 'st'.
'try'+'st'='TRYST'
'for' acts as a link.
(Other definitions for tryst that I've seen before include "Rendezvous with lover" , "cattle-fair" , "Lovers' appointment" , "An archaic lovers' meeting" , "Secret rendezvous between lovers" .)