From BiblePortal Wikipedia

Vine's Expository Dictionary of NT Words [1]

1: Δεῖ (Strong'S #1163 — Verb — dei — die, deh-on' )

an impersonal verb, signifying "it is necessary" or "one must," "one ought," is found most frequently in the Gospels, Acts and the Apocalypse, and is used (a) of a necessity lying in the nature of the case e.g.,  John 3:30;  2—Timothy 2:6; (b) of necessity brought about by circumstances, e.g.,  Matthew 26:35 , RV, "must," AV, "should;"  John 4:4;  Acts 27:21 , "should;"  2—Corinthians 11:30; in the case of Christ, by reason of the Father's will, e.g.,  Luke 2:49;  19:5; (c) of necessity as to what is required that something may be brought about, e.g.,  Luke 12:12 , "ought;"  John 3:7;  Acts 9:6;  1—Corinthians 11:19;  Hebrews 9:26; (d) of a necessity of law, duty, equity, e.g.,  Matthew 18:33 , "shouldest;"  Matthew 23:23 , "ought;"  Luke 15:32 , "it was meet;"  Acts 15:5 , "it is needful" (RV);  Romans 1:27 , RV, "was due," AV, "was meet" (of a recompense due by the law of God); frequently requiring the rendering "ought," e.g.,  Romans 8:26;  12:3;  1—Corinthians 8:2; (e) of necessity arising from the determinate will and counsel of God, e.g.,  Matthew 17:10;  24:6;  26:54;  1—Corinthians 15:53 , especially regarding the salvation of men through the death, resurrection and ascension of Christ, e.g.,  John 3:14;  Acts 3:21;  4:12 . See Behove , No. 2 (where see the differences in the meanings of synonymous words), Meet , Need , Needful , Ought , Should.

2: Ὀφείλω (Strong'S #3784 — — opheilo — of-i'-lo, of-i-leh'-o )

"to owe," is rendered "must ... needs" in  1—Corinthians 5:10 . See Behove , No. 1.

 Mark 14:49 Hebrews 13:17 2—Peter 1:14 1—Peter 4:17 Hebrews 4:6 John 6:28

Webster's Dictionary [2]

(1): ( n.) Being in a condition of dangerous frenzy, usually connected with sexual excitement; - said of adult male elephants which become so at irregular intervals.

(2): ( v. i. / auxiliary) To be obliged; to be necessitated; - expressing either physical or moral necessity; as, a man must eat for nourishment; we must submit to the laws.

(3): ( v. i. / auxiliary) To be morally required; to be necessary or essential to a certain quality, character, end, or result; as, he must reconsider the matter; he must have been insane.

(4): ( n.) The expressed juice of the grape, or other fruit, before fermentation.

(5): ( n.) Mustiness.

(6): ( v. t. & i.) To make musty; to become musty.

(7): ( n.) An elephant in must.

(8): ( n.) The condition of frenzy.

King James Dictionary [3]


1. To be obliged to be necessitated. It expresses both physical and moral necessity. A man must eat for nourishment, and he must sleep for refreshment. We must submit to the laws or be exposed to punishment. A bill in a legislative body must have three readings before it can pass to be enacted. 2. It expresses moral fitness or propriety, as necessary or essential to the character or end proposed. "Deacons must be grave," "a bishop must have a good report of them that are without."  1 Timothy 3

MUST, n. L. mustum Heb. to ferment.

New wine wine pressed from the grape but not fermented.

MUST, To make moldy and sour.

MUST, To grow moldy and sour to contract a fetid smell.