1) Aeriform 2) Aerosolised 3) Aerosolized 4) Airlike 5) Evaporated 6) Foamy 7) Frothy 8) Gasified 9) Gassy 10) In the form of vapor 11) Like certain elements 12) Like chlorine and fluorine 13) Like helium 14) Like hydrogen and chlorine 15) Like krypton 16) Like neon 17) Like neon or nitrogen 18) Like nitrogen and neon 
• (a.) In the form, or of the nature, of gas, or of an aeriform fluid. • (a.) Lacking substance or solidity; tenuous.
Of the nature of gas. ... (05 Mar 2000) ... 
Gas'e·ous adjective [ From Gas . Confer French gazeux .] 1. In the form, or of the nature, of gas, or of an aëriform fluid. 2. Lacking substance or solidity; tenuous. 'Unconnected, gaseous information.' Sir J. Stephen. 
Type: Term Pronunciation: gas′ē-ŭs Definitions: 1. Of the nature of gas.
[adj] - existing as or having characteristics of a gas
to contain or be made of gas
in a gas-like state; not solid, not liquid - like steam
adjective existing as or having characteristics of a gas; `steam is water is the gaseous state`