0
Beguile isn't a noun, so it doesn't have a plural. Beguile is a verb. The noun form is beguiler, for which the plural is beguilers.
Deceive is a good synonym for beguile. Others are fool and trick.
The antonym of beguile is bore or repel, because beguile means attractive, charming, or bewitching.
He was beguiled by her charms into believing lies about his wife.
The Word is Latin.