1A small round pocket of air that forms in or on the surface of a liquid, such as soap suds or the foam on beer. 「あぶく」 is a more colloquial reading.
洗面台に泡がたくさん残っている。
There are a lot of suds left in the sink.
ビールの泡がきめ細かくておいしそうだ。
The beer has a fine head of foam and looks delicious.
石鹸で手を洗うと白い泡が立つ。
When you wash your hands with soap, white bubbles form.
波が岩に当たって白い泡ができた。
The waves hit the rocks and formed white foam.