Gives lengthy show of respect, seeing weapon (7)
I believe the answer is:
longbow
'weapon' is the definition.
(I know that Longbow is or was a bow)
'gives lengthy show of respect' is the wordplay.
I cannot really understand how this works, but
'lengthy' could be 'long' (synonyms) and 'long' is found within the answer.
'of' could be 'o' and 'o' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'seeing' acts as a link.
Can you help me to learn more?
(Other definitions for longbow that I've seen before include "Robin Hood's weapon" , "Decisive weapon at Agincourt" , "Medieval weapon" , "Archer's weapon" , "missile-launcher" .)