Work for French joiner, holding airline up? (5)
I believe the answer is:
exert
'work' is the definition.
(thesaurus)
'french joiner holding airline up?' is the wordplay.
'french joiner' becomes 'et' ('and' in French).
'holding' indicates putting letters inside.
'airline' becomes 'rex' (I can't justify this - if you can you should give a lot more credence to this answer).
'up?' is a reversal indicator (I've seen 'up' mean this (in down clue: letters go upwards)).
'rex' backwards is 'xer'.
'et' placed around 'xer' is 'EXERT'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for exert that I've seen before include "Expend" , "Strive" , "Bring into use, apply" , "Cartoon 4 across" , "Wield - apply" .)