HYPO Meaning of HYPO in English hy ‧ po /ˈhaɪpəʊ $ -poʊ/ BrE AmE noun ( plural hypos ) [countable] informal [ Date: 1900-2000 ; Origin: hypodermic ] a ↑ hypodermic Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012