Hypo/haɪpəʊ,haɪpə,haɪˈpɑː/ Definition 1 of 4Pro Tip 1/2Medical Context Use 'hypo' for medical equipment or actions, often in a healthcare setting. The doctor decided to use a hypo for the vaccine. Pro Tip 2/2Medical Expert 'Hypo' implies the speaker has medical knowledge or authority. She grabbed a hypo from the tray efficiently.