vac/van/void

empty

Spelled vac, van, void · vacuus 'empty'; vacare 'be empty or free'; vanus 'empty, vain'

Latin vacuus means empty: a vacant room lacks occupants, a vacuum lacks matter, and vacuous talk lacks ideas.

Words built from it

vacant — empty or unoccupied
vac (empty) + -ant (being)
vacuous — lacking meaningful thought or content
vac (empty) + -ous (having the quality of)
vacuum — a space containing no matter, or very little matter
vac (empty) + -um (noun ending)
evacuate — remove people from a dangerous place
e- (out; form of ex-) + vac (empty) + -ate (make)
evanescent — quickly fading or disappearing
e- (away; form of ex-) + van (empty) + -escent (becoming)
vanish — disappear from sight or cease to exist
van (empty) + -ish (become)
vanity — excessive pride in one's appearance or achievements
van (vain) + -ity (state or quality)
void — empty; without legal force
void (empty)

vacillate — From Latin vacillare, 'sway or stagger.' It means waver between choices and does not descend from the root meaning 'empty.'