If "inflate" means to increase in size or volume:
* Deflate
* Shrink
* Reduce
* Contract
If "inflate" means to overestimate or exaggerate:
* Deflate
* Understate
* Downplay
* Minimize
If "inflate" means to increase the price of something:
* Deflate
* Reduce
* Lower
* Discount
Choose the best antonym based on the specific meaning of "inflate" in your context.