Enables beta-galactosidase activity and galactoside binding activity. Involved in galactose catabolic process; response to Thyroglobulin triiodothyronine; and response to cortisone. Located in lysosome. Human ortholog(s) of this gene implicated in GM1 gangliosidosis (multiple) and mucopolysaccharidosis IV (multiple). Orthologous to human GLB1 (galactosidase beta 1). [provided by Alliance of Genome Resources, Apr 2022]