Be careful with the knife; its edge is very sharp.

Having a fine edge or point that can cut or pierce.
Her new scissors are very sharp.
Be careful, the needle is sharp.
The pencil needs a sharp point.
sharp edge
sharp point
sharp knife
pointed
keen
honed
She is a real sharp when it comes to coding.

A person or thing that is highly skilled or proficient in a particular area.
He is a sharp in math.
She is a sharp negotiator.
They are a sharp at chess.
a real sharp
quite a sharp
a natural sharp
expert
prodigy
whiz
The drawing had sharp lines and clear details.

Clear and distinct in outline or detail.
The knife is very sharp.
Her mind is sharp and quick.
The image has sharp focus.
sharp edge
sharp contrast
sharp pain
clear
defined
distinct