Nus (נוּס) is the primary Hebrew verb for fleeing — rapid departure from a threatening situation. It covers the flight of soldiers from battle, escape from a city about to be destroyed, and the dispersal of enemies before God. The word conveys urgency and sometimes shame (fleeing in defeat), though it can also be wisdom (flee from Sodom!).
The most dramatic uses of nus include Lot's flight from Sodom (Genesis 19:20, 'I cannot escape/flee there') and the standard military report 'the men of Israel fled before the Philistines' (1 Samuel 4:10). Psalm 104:7 uses it poetically of the waters fleeing before God at creation. Numbers 35 establishes 'cities of refuge' where an accidental manslayer could nus — flee for safety — pointing to Christ as the ultimate refuge. Joseph's flight (nus) from Potiphar's wife (Genesis 39:12) provides the NT paradigm for fleeing sexual immorality (1 Corinthians 6:18 — 'flee porneia'; 2 Timothy 2:22 — 'flee youthful passions').
The biblical theology of nus is more nuanced than mere cowardice. The wise know what to flee from (sin, danger, Sodom) and what to run toward (God as refuge, the city of refuge). Joseph's flight is credited as virtue, not weakness. The Psalms use nus for enemies of God scattering before His presence (Psalm 68:1). The day of the LORD will be a day when wickedness finally has nowhere to flee — and those who have fled to Christ will find their refuge secure.