English - Omen

augury, foreboding, harbinger, portent, prophecy

Hebrew - אָמַן - Omen

verily, truly, faithful, confirm, support,

This word has a strange history among different languages. Mixed is the word omen with augury, some tongues showing the first form, some the last. Omen is found in Latin (into antiquity), Swedish, Danish, Dutch, German, Polish, and Hungarian, while augury is found in Spanish, French, Portuguese, Italian, Romanian, and Welsh. The use varies not by strict language family decendency but apparently by borrowing from one to another. The Celtic languages use a different form altogether.

From TWOT: (The numbers refer to Strong's Exhaustive Concordace.)

OT:539,OT:547, amen: to confirm, support, uphold (Qal); to be established, be faithful (Niphal); to be certain, i.e. to believe in (Hiphil). OT:544, (‎omen‎): faithfulness.

OT:543, (amen): verily, truly, amen.

OT542, (omman): steady-handed one, artist.

OT529, (emun): faithful, trusting.

OT530, (emuna): firmness, fidelity, steadiness.

OT545, (omna): bringing up, nourishment.

OT546, (omna): verily, truly.

OT548, (amana): faith, support, sure, certain.

OT552, (umnam): verily indeed.

OT551, (omnam): verily, truly.

OT571, (emet): firmness, truth.

From these references one can find the appropriate passage in Strong.

From BDB:

One can compare cognates in Arabic, (amina, amuna), Aramaic, (aman), Ethiopic, (amna) and Assyrian, showing the very ancient use of the term.

From TWOT:

This very important concept in biblical doctrine gives clear evidence of the biblical meaning of "faith" in contradistinction to the many popular concepts of the term. At the heart of the meaning of the root is the idea of certainty. And this is borne out by the NT definition of faith found in Heb 11:1.

The basic root idea is firmness or certainty. In the Qal it expresses the basic concept of support and is used in the sense of the strong arms of the parent supporting the helpless infant. The constancy involved in the verbal idea is further seen in that it occurs in the Qal only as a participle (expressing continuance). The idea of support is also seen in 2 Kings 18:16, where it refers to pillars of support.

In the Hiphil (causative), it basically means "to cause to be certain, sure" or "to be certain about," "to be assured." In this sense the word in the Hiphil conjugation is the biblical word for "to believe" and shows that biblical faith is an assurance, a certainty, in contrast with modern concepts of faith as something possible, hopefully true, but not certain.