Synonyms of airtight

Adjective

1. airtight, air-tight, invulnerable (vs. vulnerable)

usage: having no weak points; "an airtight defense"; "an airtight argument"

2. airtight, air-tight, gas-tight, tight (vs. leaky)

usage: not allowing air or gas to pass in or out

Definition and meaning of airtight (Dictionary)