This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A sealed, airtight chamber, such as in a manned spacecraft or submarine, used to provide access to and from the sealed area without allowing air out or water in.

n. a chamber that provides access to space where air is under pressure

"Step Twelve: Gently peel soap mold from sides of soap until airlock is broken."

chamber   

hatch    hatchway    turbolift    bulkhead    hangar    cockpit    elevator    passageway    ramp    transporter