Himself-Hisself | Commonly Confused Words

Himself

/ɪm'self/

Used to refer to a man, boy, or male animal when the subject and object of the verb are the same person or animal

He was beside himself.Sikes himself is sure to show up soon!"And he had been thrilled in spite of himself.

This word has no antonyms

A nonstandard form used for 'himself' referring to the same person (male) who is the object of a verb or preposition and is the same as the subject.

"Himself" is the standard form while "hisself" is considered nonstandard and dialectal.
"Himself" is used in formal and written English, whereas "hisself" might be heard in colloquial contexts.
People often say "hisself" when they are naturally imitating the possessive construction of "his" plus "self."