noun
male bathhouse attendant
Historical term for a male attendant in a public bathhouse (sento), who would scrub customers' backs, wash hair, and sometimes provide other services. Now largely obsolete.
江戸時代の銭湯には、三助と呼ばれる男性の湯浴み係がいた。
In Edo-period public bathhouses, there were male attendants called sansuke.
Female bathhouse attendant, often with additional connotations; 三助 is specifically male.
The exact origin is uncertain. The kanji 三助 may be a name-like compound, but the historical derivation is not clearly documented.