(rhetorical question, colloquial, childish) Assertion that an insult made by the party to whom the phrase is directed is actually true of that party, and not of the person using the phrase. Usually considered to be a playground taunt.

(colloquial, rhetorical question) Alternative form of am I right, implying the speaker can't possibly be wrong.

Indicates that a person's underwear is showing.

Alternative form of I know you are but what am I

An affirmation of affection or deep caring, especially to a family member. / An affirmation of romantic feeling to a lover or spouse. / A platonic expression of strong inclination or liking to a friend.

(history) The war from 1914 to 1918 between the Entente Powers of the British Empire, Russian Empire, France, Italy, the United States and other allied nations, against the Central Powers represented by the German Empire, Austria-Hungary, the Ottoman Empire, and Bulgaria.

I believe that is the case, but am not certain.

used after a statement to indicate an emphatic or ironic negative

(chiefly Britain, idiomatic) I am mistaken; I thought that what I said (or wrote) was true, but I have just realised that it is not.

A phrase used in response to a question or command in which the target person does not know the answer to or how to respond.