Is it ensure, insure, or assure?
Old English word "speech, talk, utterance, word," from Proto-Germanic *wurdan (cf. Old Saxon, Old Frisian word, Dutch woord, Old High German, German wort, Old Norse orð, Gothic waurd), from PIE *were- "speak, say" (see verb).
The meaning "promise" was in Old English, as was the theological sense. In the plural, the meaning "verbal altercation" (as in to have words with someone) dates from mid-15c. Word processor first recorded 1973; word processing is from 1984; word wrap is from 1977. A word to the wise is from Latin phrase verbum sapienti satis est "a word to the wise is enough." Word of mouth is recorded from 1550s.
It is dangerous to leave written that which is badly written. A chance word, upon paper, may destroy the world. Watch carefully and erase, while the power is still yours, I say to myself, for all that is put down, once it escapes, may rot its way into a thousand minds, the corn become a black smut, and all libraries, of necessity, be burned to the ground as a consequence. [William Carlos Williams, "Paterson"]
(Heb. 4:12, etc.). The Bible so called because the writers of its several books were God's organs in communicating his will to men. It is his "word," because he speaks to us in its sacred pages. Whatever the inspired writers here declare to be true and binding upon us, God declares to be true and binding. This word is infallible, because written under the guidance of the Holy Spirit, and therefore free from all error of fact or doctrine or precept. (See INSPIRATION ØT0001884; BIBLE.) All saving knowledge is obtained from the word of God. In the case of adults it is an indispensable means of salvation, and is efficacious thereunto by the gracious influence of the Holy Spirit (John 17:17; 2 Tim. 3:15, 16; 1 Pet. 1:23).