Webster's Revised Unabridged Dictionary · 1913

Flee

Flee (flē) , intransitive verb

[Old English fleon, fleen, Anglo-Saxon fleón (imperf. fleáh); akin to Dutch vlieden, Old High German & Old Saxon fliohan, German fliehen, Icelandic flȳja (imperf. flȳei), Danish flye, Swedish fly (imperf. flydde), Gothic þliuhan. r84. Compare Flight.]

To run away, as from danger or evil; to avoid in an alarmed or cowardly manner; to hasten off; -- usually with from. This is sometimes omitted, making the verb transitive.
[He] cowardly fled, not having struck one stroke. — Shakespeare
Flee fornication. — 1 Cor. vi. 18
So fled his enemies my warlike father. — Shakespeare

When great speed is to be indicated, we commonly use fly, not flee; as, fly hence to France with the utmost speed. “Whither shall I fly to 'scape their hands?” Shak. See Fly, v. i., 5.