1) a kind of substance that passes into the blood and encourages physical development etc (hormone)

2) a space completely empty of substance or gas(es); a space in a container from which (almost all) the air has been pumped out; to use a vacuum cleaner to clean (a carpet etc) (vacuum)

3) the soft yellow substance produced by bees and used for making honeycomb cells; a kind of substance similar to beeswax, used for making candles etc; to cover, polish or treat (furniture, wood etc) with wax; (of the moon) to show an increasing bright area (wax)