泉 is one of the most commonly used Japanese kanji, and it also has a lot of special readings in addition to the standard onyomi and kunyomi readings.
ONYOMI 音読み
いずみ izumi
KUNYOMI 訓読み
セン sen
Examples
泉はおよそ170フィートの高さまで温水を吹き出す。The fountain sends hot water to a height of 170 feet.彼はその泉の水を飲んだ。He drank from the spring.彼らはその泉で喉の渇きをいやした。They satisfied their thirst at the spring.その男は知識の泉ともいうべき人だった。The man was a fountain of knowledge.