my Definition

my
adj

1. Belonging or relating to me.

Example: my book
2. Used with nouns in various exclamations

Example: My gosh!
Example: My foot!
3. old use
Used in respectful terms of address such as my lord.
4. Used in rather old-fashioned, affectionate or patronizing terms of address such as my dear.

exclamation

1. Expressing surprise or amazement

Example: My, how grown-up you look!
Form: my word (also)
Form: my goodness
Form: my God (more strongly)

Etymology: 12c, from Anglo-Saxon min genitive of me¹.