My

Multiple Entries:
  MY    my    my-    myo-  

Concise Oxford English Dictionary © 2008 Oxford University Press:
MY

▶abbreviation motor yacht.

Concise Oxford English Dictionary © 2008 Oxford University Press:
my/mʌɪ/

▶possessive determiner

• 1 belonging to or associated with the speaker.

  ■ used with forms of address in affectionate, sympathetic, humorous, or patronizing contexts.

• 2 used in various expressions of surprise.

– phrases
My Lady (or Lord) a polite form of address to certain titled people.

– origin ME mi, reduced from min, from OE mīn (see mine1).

Concise Oxford English Dictionary © 2008 Oxford University Press:
my-

▶combining form variant spelling of myo- shortened before a vowel (as in myalgia).

Concise Oxford English Dictionary © 2008 Oxford University Press:
myo- /ˈmʌɪəʊ/ (also my- before a vowel)

▶combining form of muscle; relating to muscles: myocardium.

– origin from Gk mus, mu- ‘mouse or muscle’.