What is the meaning of 'm?

Am, used especially in I'm.

Various forms of be.

Alternative form of 'em.

Represents the word madam or ma'am when used as a formal address of a female; as in yes'm and no'm.

a

the

contraction of me

my

me

contraction of hem

Reduced form of jam (“you, you all”, subject)

my

me

contraction of ddim (“not”)

Source: wiktionary.org