1fill (a balloon, tyre, or other expandable structure) with air or gas so that it becomes distended:never use an air line on a garage forecourt to inflate your tyres
[no object] become distended with air or gas:the mattress inflated
2increase (something) by a large or excessive amount:objectives should be clearly set out so as not to duplicate work and inflate costs
exaggerate:numbers have been grossly inflated by the local press
3bring about inflation of (a currency) or in (an economy):he has inflated the money supply to allow companies to continue in their old ways