From WordNet (r) 3.0 (2006):
zero
adj 1: indicating the absence of any or all units under
consideration; "a zero score" [syn: zero, 0]
2: having no measurable or otherwise determinable value; "the
goal is zero population growth"
3: indicating an initial point or origin
4: of or relating to the null set (a set with no members)
n 1: a quantity of no importance; "it looked like nothing I had
ever seen before"; "reduced to nil all the work we had
done"; "we racked up a pathetic goose egg"; "it was all for
naught"; "I didn't hear zilch about it" [syn: nothing,
nil, nix, nada, null, aught, cipher, cypher,
goose egg, naught, zero, zilch, zip, zippo]
2: a mathematical element that when added to another number
yields the same number [syn: zero, 0, nought, cipher,
cypher]
3: the point on a scale from which positive or negative
numerical quantities can be measured [syn: zero, zero
point]
4: the sight setting that will cause a projectile to hit the
center of the target with no wind blowing
v 1: adjust (an instrument or device) to zero value
2: adjust (as by firing under test conditions) the zero of (a
gun); "He zeroed in his rifle at 200 yards" [syn: zero,
zero in]