Short, extremely showy gesture of respect (6)
I believe the answer is:
curtsy
'gesture of respect' is the definition.
(I've seen this in another clue)
'short extremely showy' is the wordplay.
'short' becomes 'curt' (synonyms).
'extremely' means to remove the middle letters (letters on the extremes of the word are used).
'showy' with its centre removed is 'sy'.
'curt'+'sy'='CURTSY'
(Other definitions for curtsy that I've seen before include "Bend the knee in respect" , "Female obeisance bending the knees" , "Woman's formal greeting" , "Gesture of respect by women" , "Kind of respectful bob made by women" .)