From the Italian word for 'boy'. Pronounced 'poo-toh' or 'poot-taw'. Plural is putti (pronounced 'poo-tee').
In English, we use 'putto' to refer to a chubby, naked infant boy in a classical or renaissance painting. They are usualy, but not necessarily, winged.
If they have little bows (the shooting kind) with them they are called cupids, or sometimes amoretti. If they are representing an angel, they are cherubs.