From BiblePortal Wikipedia

Vine's Expository Dictionary of NT Words [1]

1: Βλέπω (Strong'S #991 — Verb — blepo — blep'-o )

"to see," is applied to mental vision, and is sometimes used by way of warning "to take heed" against an object,  Mark 8:15;  12:38;  Acts 13:40;  Philippians 3:2 (three times); in   Colossians 2:8 , RV, "take heed," marg., "see whether." See Behold.

2: Προσέχω (Strong'S #4337 — Verb — prosecho — pros-ekh'-o )

lit., "to hold to" (pros, "to," echo, "to have, to hold"), hence, "to turn one's mind or attention to a thing by being on one's guard against it" is translated "beware" in  Matthew 7:15;  10:17;  16:6,11,12;  Luke 12:1;  20:46 . See Attend , Heed , Regard.

3: Φυλάσσω (Strong'S #5442 — Verb — phulasso — foo-las'-so )

"to guard, watch, keep," is used, in the Middle Voice, of being "on one's guard against" (the Middle V. stressing personal interest in the action),  Luke 12:15 , "beware of," RV, "keep yourselves from," as in  Acts 21:25; in  2—Timothy 4:15 , "be thou ware;" in  2—Peter 3:17 , "beware." See Guard , Keep , Observe , Save.

King James Dictionary [2]


1. Literally, to restrain or guard one's self from. Hence, to regard with caution to restrain one's self from anything that may be dangerous, injurious or improper to avoid to take care followed by of before the thing that is to be avoided.

Beware of all, but more beware of man.

Beware of false prophets beware of the leaven of the Pharisees beware of the concision.

2. To have a special regard to.

Behold, I send an angel before thee--beware of him, and obey his voice.  Exodus 23

This is unusual and hardly legitimate.

This word though here admitted as a verb, from the Saxon,is rarely used as a verb in fact or if a verb, is now never used except in the imperative mode It is a compound of be and the Old Eng. ware, now wary. Be wary of danger. Hence it cannot be used with did, like a regular verb, nor with be, in any of its inflections, he is beware for this would be to use the substantive verb twice before ware and wary, is and be. Ben Jonson however has used the word in the third person. He bewares to act. But it has no past tense or participle, and therefore, if admitted as a verb, it is defective,and used only in the imperative mode, or after an auxiliary.

We must beware of excess.

Webster's Dictionary [3]

(1): (v. i.) To have a special regard; to heed.

(2): (v. t.) To avoid; to take care of; to have a care for.

(3): (v. i.) To be on one's guard; to be cautious; to take care; - commonly followed by of or lest before the thing that is to be avoided.