Sewage
来自Big Physics
mid 19th century: from sewer1, by substitution of the suffix -age.
wiktionary
From sewer(“system of pipes used to remove human waste and to provide drainage”) + -age or from sew(“to drain or draw off water”) + -age.
etymonline
sewage (n.)
1818, from sew (v.) "to drain, draw off water" (late 15c., from sewer (n.1)) + -age.
