泌 has two pronunciations: bì and mì. The bì reading (as given here) appears primarily in place names such as 泌阳 (Bìyáng, a county in Henan) and in the name of an ancient river. It does NOT mean 'secrete' — that meaning belongs to the mì reading, used in words like 分泌 (fēnmì, 'to secrete'). The entry's English gloss is likely a mismatch with the pinyin.