Snatch child having a sleep? (6)
I believe the answer is:
kidnap
'snatch' is the definition.
(I know that snatch can be written as kidnap)
'child having a sleep?' is the wordplay.
'child' becomes 'kid' (synonyms).
'having' is a charade indicator (letters next to each other).
'a sleep?' becomes 'nap' (a nap is a short sleep).
'kid'+'nap'='KIDNAP'
(Other definitions for kidnap that I've seen before include "Shanghai, abduct" , "Seize, usually for ransom" , "deprive it of liberty" , "Small island" , "Take person prisoner for ransom" .)