1. Mail that includes letters and postcards and packages sealed against inspection
   - first class, 1st class, first-class mail

Type of: mail

• quadrivium
• quadroon
• quadrumanous
• quadrumvirate
• quadruped
• quadrupedal
• quadruple
• quadruple time
• quadruplet
• quadruplex
• quadruplicate
• quadruplication
• quadrupling
• quadruply
• quadtree
• quaestor
• quaff
• quaffer
• quag
• quagga
• quaggy
• quagmire
• quahaug
• quahog
• Quai d'Orsay