Shows small muscles around genitals, having dropped kilo (10)
I believe the answer is:
spectacles
'shows' is the definition.
(a spectacle is a show)
'small muscles around genitals having dropped kilo' is the wordplay.
'small muscles' becomes 'specs' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'around' indicates putting letters inside.
'genitals' becomes 'tackle' (tackle can mean a man's genitals).
'having dropped' suggests deleting specific letters.
'kilo' becomes 'k' (phonetic alphabet: alpha, bravo, charlie etc.).
'tackle' with 'k' taken out is 'tacle'.
'specs' placed around 'tacle' is 'SPECTACLES'.
(Other definitions for spectacles that I've seen before include "See 6" , "Viewing aid" , "(Pair of) glasses" , "splendid entertainments?" , "With which to view" .)