What does "cleanout" mean?

An opening or drain leading into a plumbing system to provide a location to insert a snake or other implement for cleaning.

What is a synonym for "cleanout"?

Common synonyms include: mucking.

noun, slang

noun, slang ·Uncommon ·College level

Noun

1
An opening or drain leading into a plumbing system to provide a location to insert a snake or other implement for cleaning.
2
A thorough cleaning that removes everything removable.
"attic, basement, and garage cleanouts [in advertisements]"
3
An enema. informal

"attic, basement, and garage cleanouts [in advertisements]"

Deverbal from clean out.