basinplug
nounUK /ˈbeɪsɪn plʌɡ/
US /ˈbeɪsɪn plʌɡ/
A basin plug is a small round stopper that keeps water in a sink.
She pulled out the basin plug so the dirty water could drain away.
OTHER MEANINGS
2. A rubber or plastic stopper sized to fit the waste hole of a washbasin.
The old basin plug had gone hard and no longer sealed the hole.
3. A removable cap that closes the drain opening of a basin to allow it to fill.
He forgot the basin plug, so the water ran straight out.
4. A chain-attached stopper used in a bathroom washbasin.
The basin plug dangled from its little chain beside the tap.