寿 is in 寿命 (shòumìng, lifespan), 长寿 (chángshòu, longevity), 寿司 (shòusī, sushi — borrowed from Japanese). 祝寿 means to celebrate an elder's birthday.
culture
The character 寿 is often written in decorative calligraphy and displayed at birthday celebrations for the elderly. 寿桃 (shòutáo, longevity peaches) are traditional birthday gifts.
Bottom inch radical — pictograph of a hand with a small mark below the wrist marking the pulse-point (one inch from the palm). Indexes 寿 in the measurement family alongside 对 (correct), 封 (seal), 寺 (temple). The 'measuring' sense fits longevity: a measured-out span of life.
Top of the simplified form — looks like 丰 but is a graphic stand-in for the much more layered top of traditional 壽, compressed in the 1956 reform. The visual 丰 carries an apt echo: long life is an abundance of years.
