inside out

Idioms  

1. With the inner surface turned out or revealed, as in He wore his shirt inside out . This expression dates from about 1600 and was soon used figuratively, as in He turned the verses inside out and revealed their hidden sense .

2. Extremely well, thoroughly, especially alluding to knowing something. For example, He knows this system inside out . [First half of 1900s]

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Example Sentences

While the couple knew each others' strengths and weaknesses inside out, life in the public eye often left them feeling like "passing ships in the night."

From BBC

That heat was enough to shatter a single pane window, creating the perfect opportunity for embers to enter and burn the house from the inside out.

From Los Angeles Times

He knew the line-out inside out, and now he is bringing that level of clarity to every aspect of the game.

From BBC

He turned his trouser pockets inside out, showing them to be empty.

From Literature

Richards clearly knows the ecosystem of films inside out.

From BBC