"Amino acid" doesn't really stand for anything. It's a descriptive term that combines two words:

* Amino: Refers to the amino group (-NH2), which is a key functional group found in amino acids.

* Acid: Refers to the carboxylic acid group (-COOH), another key functional group found in amino acids.

So, amino acid essentially means "a molecule containing both an amino group and a carboxylic acid group".