(n.) The act or process of rarefying; the state of being rarefied; -- opposed to condensation; as, the rarefaction of air.

Sanforizing abatement adulteration atrophy attenuation attrition blunting consumption contour plowing cultivating cultivation culture cutting damping deadening debilitation devitalization diluent dilution dissolvent dressing drying drying up dulling effemination emaceration emaciation enervation enfeeblement etherealization evisceration exhaustion extenuation fallowing fatigue furrowing harrowing hoeing inanition languishment listing mitigation parching plowing preshrinkage pruning rarefaction reduction relaxation resolutive resolvent searing shrinkage shrinking shriveling slackening softening solvent subtilization tilling wasting weakening weeding withering working