Almost come down with tranquilliser for squire (9)
I believe the answer is:
landowner
'squire' is the definition.
(I've seen this before)
'almost come down with tranquilliser' is the wordplay.
'almost' means to remove the last letter (almost the whole word is kept).
'come down' becomes 'land' (to land is to come down after flying).
'with' says to put letters next to each other.
'tranquilliser' becomes 'downer' (I've seen this before).
'land' with its final letter taken away is 'lan'.
'lan'+'downer'='LANDOWNER'
'for' is the link.
(Other definitions for landowner that I've seen before include "One with much property" , "Man of means" , "Laird" , "One with estates" , "Squire, perhaps" .)