A saccharide attached to a single amino acid by any kind of covalent bond. A glycosyl-amino-acid is a compound consisting of saccharide linked through a glycosyl linkage (O
-, or S
-) to an amino acid.
The hyphens are needed to avoid implying that the carbohydrate is necessarily linked to the amino group.
White Book, 2nd ed., p. 85 (https://www.qmul.ac.uk/sbcs/iupac/bibliog/white.html)