Son dropping new piece of cutlery (5)
I believe the answer is:
spoon
'piece of cutlery' is the definition.
(I've seen this before)
'son dropping new' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'dropping' becomes 'poo' (informal term for excrement).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
's'+'poo'+'n'='SPOON'
(Other definitions for spoon that I've seen before include "Wood formerly" , "A runcible item of cutlery?" , "No knife" , "cooking utensil" , "feeder" .)