Disappointed engineer trusted RAF (10)

I believe the answer is:

frustrated

'disappointed' is the definition.
(I know that disappointed can be written as frustrated)

'engineer trusted raf' is the wordplay.
'engineer' is an anagram indicator.
'trusted'+'raf'='trustedraf'
'trustedraf' with letters rearranged gives 'FRUSTRATED'.

(Other definitions for frustrated that I've seen before include "Disheartened" , "Prevented from progressing" , "Disappointingly unsuccessful" , "Thwarted" , "Foiled" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.