Question

what do you mean by acid

Answer 1

It is a substance with chemical properties like turning the litmus paper from blue to red.
It is sour in taste(for weak acids). as well as corrosive too(strong acids). and contains hydrogen ions(H+ ions) .
I would define it as a moleculs or an ion which is capable of donating a hydrogen or alternatively ,capable of forming a covalent bond with electrons.

It reacts with a base to form salts(or alkali) and water.

Answer 2

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A substance with particular chemical properties including turning litmus red, neutralizing alkalis, and dissolving some metals; typically, a corrosive or sour-tasting liquid of this kind.

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