Dozy/ˈdəʊzi/ Definition 1 of 2Pro Tip 1/3Tiredness Level Use 'dozy' for mild sleepiness, less strong than 'exhausted'. I'm feeling a bit dozy after that meal. Pro Tip 2/3Informal Usage 'Dozy' is informal, suitable for casual conversations, not formal writing. We all got a bit dozy after the party ended. Pro Tip 3/3Not Fully Asleep 'Dozy' implies being half-asleep or on the verge of sleeping. The warm room made me dozy as I struggled to stay awake.