Quite a few zoom lenses have a "macro" focus position but in general as already commented they will focus just slightly closer than perhaps normal giving around 0.2:1 to 0.3:1 magnification compared to macro primes giving 1:1. Brian v.
It's really the marketing team that determines whether a lens is 'macro capable' or not, unfortunately. I have a 28-105mm zoom with a 'macro' label on it that provides 1:5 magnification.