Inflate/ɪnˈfleɪt/ Definition 1 of 3Pro Tip 1/3Physical Expansion Used when something physically grows in size, often by air or gas. They watched the parade balloon inflate rapidly. Pro Tip 2/3Literal Air Literally involves filling an object with air or gas, not just making it bigger. Before diving, check to properly inflate the life jacket. Pro Tip 3/3Tangible Objects Most often used with objects that can be touched, like tyres or balloons. Always inflate the soccer ball to the recommended pressure.