Proto-Indo-European root meaning "to be strong."
It forms all or part of: ambivalence; Arnold; avail; bivalent; convalesce; countervail; Donald; equivalent; evaluation; Gerald; Harold; invalid (adj.1) "not strong, infirm;" invalid (adj.2) "of no legal force;" Isold; multivalent; polyvalent; prevalent; prevail; Reynold; Ronald; valediction; valence; Valerie; valetudinarian; valiance; valiant; valid; valor; value; Vladimir; Walter; wield.
It is the hypothetical source of/evidence for its existence is provided by: Latin valere "be strong, be well, be worth;" Old Church Slavonic vlasti "to rule over;" Lithuanian valdyti "to have power;" Celtic *walos- "ruler," Old Irish flaith "dominion," Welsh gallu "to be able;" Old English wealdan "to rule," Old High German -walt, -wald "power" (in personal names), Old Norse valdr "ruler."
The place name is from Latin Hassi/Hatti/Chatti, the Latinized form of the name of the Germanic people the Romans met in northern Germany (Greek Khattoi). The meaning of the name is unknown. Part of Arminius's coalition at the Battle of Teutoburger Wald (9 C.E.), they later merged with the Franks. They are mentioned in Beowulf as the Hetwaras. The state was annexed to Prussia in 1866 and is not to be confused with the Grand Duchy of Hesse-Darmstadt.