Meaning of the word "know your stuff" in English

What does "know your stuff" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

know your stuff

US /noʊ jʊər stʌf/
UK /nəʊ jɔː stʌf/
"know your stuff" picture

Idiom

to be very knowledgeable and skilled in a particular area or subject

Example:
You can trust her advice; she really knows her stuff when it comes to financial planning.
The new mechanic clearly knows his stuff; he fixed the engine in no time.