terh₁-
“to cross, to overcome”cross, pass through, overcome
Root for crossing/overcoming, yielding Latin trans (across), English through, thorough.
Discussion
The Proto-Indo-European root *terh₁- meant "to cross over, to pass through, to overcome." The most consequential Latin derivative is trāns "across" (from *tr̥h₁-ns), a prefix that has become one of the most productive morphemes in modern European languages: transport, translate, transcend, transform, transgress, transit, and countless others. Latin intrāre "to enter" and penetrāre continue the root directly. The Germanic branch shows equally deep penetration: English through (Old English þurh) and thorough (originally the same word) descend from this root, as does thrill (originally "to pierce through"). Sanskrit tirati "he crosses" and tīrṇa- "crossed over" confirm the Indo-Iranian branch, and the concept of spiritual crossing (avatāra, "a descent, a crossing down") carries profound religious significance. The semantic arc from physical crossing to abstract overcoming is culturally revealing: Latin trāns- treats space as something to be traversed, while English through emphasizes completeness of passage. The root encodes a worldview in which crossing a boundary was not merely motion but achievement.
Notes
Pokorny 1074-1075. English through, trans-, thrill, nostril.