See a man about a dog

Meaning

A classic, vague excuse used when you do not want to tell someone where you are going. It is typically used to leave a social situation for a private reason.

Mysterious, humorous

Used in a sentence

• I will be right back, I have to go see a man about a dog.
• Where are you heading at this hour? Oh, just seeing a man about a dog.
• If anyone asks where I went, tell them I am seeing a man about a dog.