Fighter with height and strength (5)
I believe the answer is:
might
'strength' is the definition.
(might is a kind of strength)
'fighter with height' is the wordplay.
'fighter' becomes 'mig' (fighter jet produced by Russian company MiG).
'with' means one lot of letters go next to another.
'height' becomes 'ht' (abbreviation).
'mig'+'ht'='MIGHT'
'and' is the link.
(Other definitions for might that I've seen before include "May, in the past" , "Great power/strength" , "Doubtful" , "- - and main" , "Physical strength of old" .)