endure

First recorded in 1275–1325; Middle English enduren, from Anglo-French, Old French endurer, from Latin indūrāre “to harden, make lasting,” equivalent to in- in-² + dūrāre “to last, be or become hard,” derivative of dūrus “hard”

2. See bear¹. 4. See continue.

From a word for a tree known for its hard and durable wood, we get endure, a word that evokes both lastingness (durability) and the ability to withstand or bear. Its history tells you why.
Endure comes from Old French endurer “to make hard, harden, bear.” The Old French verb is a regular development of Latin indūrāre, with the same meanings. Indūrāre is a derivative of the adjective dūrus, which has a wide range of meanings, including “hard, firm, solid, constipated, dull, obtuse, pitiless, oppressive.”
Dūrus comes from an unrecorded drūr(us), dūr- (drūr-), being the Latin development of the Proto-Indo-European root deru-, doru-, drew-, drū- “oak tree, tree,” which is very common throughout the Indo-European languages and has many variants and suffixes. In Greek, dóry means “wood, tree, tree trunk, spear”; drŷs means “tree, oak tree” (sacred to Zeus); Dōrieús “a Dorian” was “a Greek (originally) from Dōrís (the ancient Greek region of Doris, literally, Forestlands).” The Old Irish noun drūi “druid” ultimately comes from dru-wid- “strong seer”; from the variant drew-. Old Church Slavonic has drĕvo “tree.” In Germanic, drew- becomes triu “tree, wood,” which becomes trēow in Old English (English tree ).

C14: from Old French endurer, from Latin indūrāre to harden, from dūrus hard