1.
handwashing, washing by hand
The act of washing one's hands, or washing something by hand rather than by machine.
手洗い has two distinct meanings: the literal act of washing hands and a polite euphemism for the restroom.
SENSE 1 — HANDWASHING:
SENSE 2 — RESTROOM:
Used as a polite, indirect way to say 'toilet.' Common in formal settings and signage.