1. By comparing languages
   "she studied the phenomenon cross-linguistically"

See also: cross-linguistic

• Declaration of Independence
• declarative
• declarative mood
• declarative sentence
• declaratory
• declaratory sentence
• declare
• declare oneself
• declared
• declarer
• declass
• declassification
• declassified
• declassify
• declaw
• declension
• declensional
• declinable
• declination
• decline
• decline in quality
• decliner
• declinometer
• declivitous
• declivity