1. Relying on observation or experiment
   - experimental, observational

See also: empiric, empirical

• quadrivalent
• quadrivial
• quadrivium
• quadroon
• quadrumanous
• quadrumvirate
• quadruped
• quadrupedal
• quadruple
• quadruple time
• quadruplet
• quadruplex
• quadruplicate
• quadruplication
• quadrupling
• quadruply
• quadtree
• quaestor
• quaff
• quaffer
• quag
• quagga
• quaggy
• quagmire
• quahaug