know inside and out
To know (something or someone) very thoroughly.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“He knows the city streets inside and out.”
“After working at the company for ten years, she knows the software inside and out.”
“The seasoned detective claimed he knew the criminal's habits inside and out, allowing him to predict the next move with ease.”
- 01
as far as one knows
To the best of one's knowledge, as far as someone knows or possible information to be gathered about the topic, subject, aspect, or situation.
- 02
as you know
as it is already known.
- 03
fuck if I know
I have no idea whatsoever
- 04
fuck knows
I don't know; nobody knows; it is unclear.
- 05
hell if I know
Synonym of I don't know.
- 06
I don't know about that
I am not sure that I agree; expressing doubt or skepticism.
- 07
I hardly know her
A joking retort that draws attention to the possibility of sexual innuendo when a word ends with a schwar.
- 08
it takes one to know one
Expressing the same underlying character-judgment themes as pot calling the kettle black or set a thief to catch a thief.
Last updated August 10, 2026