sump

A sump is a pit, tank, or low space where water, oil, or other liquid collects. In many houses, it is the basin in the basement that gathers water, and a sump pump pushes that water away before it can cause flooding. The idea is simple: it is the place liquids drain down into and collect in.

You can also meet the word in machines. In an engine, the sump is the part at the bottom where oil gathers before it is pumped around again. In each case, it names the low place where liquid settles and waits to be removed or reused.

A sump is a pit, basin, or lowest compartment made to collect liquid. Most people know the word from home drainage systems: water seeps into a low basin, usually in a basement or crawl space, and a sump pump removes it before the area floods. It is not a place for storing water by choice; it is the place where unwanted liquid gathers so it can be dealt with.

The word is also common in mechanical and industrial contexts. In an engine, the sump is the bottom part where lubricating oil collects after moving through the system; this is why it is often closely associated with the oil pan. In other equipment or drainage systems, a sump can be any low chamber where liquid, sludge, or sediment settles before being pumped out, filtered, or drained away.

The central idea stays the same across these uses: it is the low point where material collects. That is why the word can also be used for the lowest part of a ship or another structure where water gathers. In careful modern English, the word is mainly practical and technical rather than figurative. Whether you are talking about a wet basement, an engine, or a drainage system, a sump is the place at the bottom where liquid ends up.