1. Not allowing air or gas to pass in or out
   - airtight, air-tight

See also: tight

• cxxv
• cxxx
• cxxxv
• cy pres
• cy pres doctrine
• Cy Young
• Cyamopsis
• Cyamopsis psoraloides
• Cyamopsis tetragonolobus
• Cyamus
• cyan
• cyanamid
• cyanamide
• cyanate
• cyanic acid
• cyanide
• cyanide group
• cyanide poisoning
• cyanide process
• cyanide radical
• cyanine
• cyanine dye
• cyanite
• cyano group
• cyano radical