intestate adj.

word-forming element meaning "not, opposite of, without" (also im-, il-, ir- by assimilation of -n- with following consonant, a tendency which began in later Latin), from Latin in- "not," cognate with Greek an-, Old English un-, all from PIE root *ne- "not."

In Old French and Middle English often en-, but most of these forms have not survived in Modern English, and the few that do (enemy, for instance) no longer are felt as negative. The rule of thumb in English has been to use in- with obviously Latin elements, un- with native or nativized ones.

late 13c., "last will disposing of property," from Latin testamentum "a last will, publication of a will," from testari "make a will, be witness to," from testis "witness," from PIE *tri-st-i- "third person standing by," from root *tris- "three" (see three) on the notion of "third person, disinterested witness."

Use 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 diatheke and kaine diatheke. Late Latin testamentum in this case was a confusion of the two meanings of Greek diatheke, which meant both "covenant, dispensation" and "will, testament," and was used in the former sense in the account of the Last Supper (see testimony) but subsequently was interpreted as Christ's "last will."

"condition of dying without leaving a valid will," 1740, from intestate + -acy.