Reliable place ahead of fleet (9)
I believe the answer is:
steadfast
'reliable' is the definition.
(I've seen this in another clue)
'place ahead of fleet' is the wordplay.
'place' becomes 'stead' (synonyms).
'ahead of' says to put letters next to each other (some letters go in front of others).
'fleet' becomes 'fast' (similar in meaning).
'stead'+'fast'='STEADFAST'
(Other definitions for steadfast that I've seen before include "Resolutely firm" , "Constant and resolute" , "Fixed, unyielding" , "Firm and unwavering" , "Firm and dependable" .)