• 分泌ぶんぴつ — secretion; release of a substance from the body
• 内分泌ないぶんぴつ — internal secretion; hormones produced inside the body
• 泌尿器ひにょうき — urinary organs
• 泌尿器科ひにょうきか — urology department in a hospital

On the left, the radical 氵 shows water or liquid. On the right, the sound part hints at the reading ヒツ and suggests something that must come out little by little. Together, 泌 is used for liquids that seep, ooze, or are secreted, especially inside the body.