Amino is a chemistry word that almost never stands alone — you'll meet it as part of 'amino acid.' Amino acids are small building-block molecules that link together to form proteins, which your body needs for muscles, skin, hair, and much more. When you see 'amino' on a supplement bottle or in a biology class, it's pointing to this chemical group (called an amine group) attached to the molecule.

胺基（化學用語，常見於「胺基酸」）