1) Capable of being inflated 2) Expansive 1) Expansive 2) Infl 
An inflatable is an object that can be inflated with a gas, usually with air, but hydrogen, helium and nitrogen are also used. One of several advantages of an inflatable is that it can be stored in a small space when not inflated, since inflatables depend on the presence of a gas to maintain their size and shape. Function fulfillment per mass used...
• (a.) That may be inflated.
A dinghy or raft that can be filled with air for use then deflated for stowage.
In·flat'a·ble adjective That may be inflated. 
[adj] - designed to be filled with air or gas
adjective designed to be filled with air or gas; `an inflatable mattress`; `an inflatable boat`
capable of being inflated. · designed or built to be inflated before use.