mine

We don’t traditionally think of the possessive word mine as having synonyms, but there are several situations in which it can replace—or be replaced with—another term.

my

Sometimes you can reword what you’re saying to use my instead of mine. For example, instead of saying This seat is mine, you could say This is my seat. 

Mine is also an archaic form of my. This was especially used before a word beginning with a vowel sound, as in mine eyes, or following a noun, as in I must do what is duty mine. 

my own 

The phrase my own is sometimes used as a more emphatic way of saying mine, as in The fault is my own.

ours

Instead of saying things like This house is mine and hers, we usually use the plural form ours, as in This house is ours.