Definition of acids:
(n) :
(chemistry) Any compound which yields H+ ions (protons) when dissolved in water; an Arrhenius acid.
(n) :
(chemistry) Any compound that easily donates protons to a base; a Brønsted acid.
(n) :
(chemistry) Any compound that can accept a pair of electrons to form a covalent bond; a Lewis acid.
(adj) :
Of or pertaining to an acid; acidic.
(adj) :
Sour, sharp, or biting to the taste; tart; having the taste of vinegar.
(n) :
A sour substance.