Weird guys start toying with the left-over piece (7)
I believe the answer is:
oddment
'piece' is the definition.
(I've seen this before)
'weird guys start toying with the left-over' is the wordplay.
'weird guys' becomes 'men' (guy can mean a man. I am not sure about the 'weird' bit.).
'start' suggests taking the first letters.
'with' means one lot of letters go next to another.
'the left over' becomes 'odd' (I've seen this before).
The first letter of 'toying' is 't'.
'men'+'t'='ment'
'ment' after 'odd' is 'ODDMENT'.
Can you help me to learn more?
(Other definitions for oddment that I've seen before include "a bit spare" , "Leftover item" , "Leftover piece" , "Curiosity, peculiarity" , "Scrap" .)