Origin and history of contest

"disputed, made the object of contention or competition," 1670s, past-participle adjective from contest (v.). Specifically of elections from 1771, American English.

late 13c., in law, "last will, expressing the final disposition of one's property," from Latin testamentum "a last will, publication of a will," from testari "make a will, be witness to," from testis "witness," generally accepted to be from PIE *tri-st-i- "third person standing by," from root *tris- "three" (see three) on the notion of "third person, disinterested witness."

Use of testament in reference to the two divisions of the Bible (early 14c.) is from Late Latin vetus testamentum and novum testamentum, loan-translations of Greek palaia diathēkē and kainē diathēkē. But here Late Latin testamentum is a confusion of the two meanings of Greek diathēkē, which meant both "covenant, dispensation" and "will, testament." Testament had been used in the sense of "covenant between God and mankind" in English from early 14c. (as in the account of the Last Supper; see testimony), but the word subsequently was interpreted as Christ's "last will."