A discoloured spot or area.
A reagent or dye used to stain microscope specimens so as to make some structures visible.
Any of a number of non-standard tinctures used in modern heraldry.
A blemish on one's character or reputation.
A substance used to soak into a surface and colour it.
To cause to seem inferior or soiled by comparison.
To coat a surface with a stain
To treat (a microscopic specimen) with a dye, especially one that dyes specific features
To taint or tarnish someone's character or reputation
To discolour.
To become stained; to take a stain.
A region of space that contains no matter.
The condition of rarefaction, or reduction of pressure below that of the atmosphere, in a vessel, such as the condenser of a steam engine, which is nearly exhausted of air or steam, etc.
An emptiness in life created by a loss of a person who was close, or of an occupation.
A vacuum cleaner.
An exercise in which one draws their abdomen towards the spine.
A spacetime having tensors of zero magnitude.
To optimise a database or database table by physically removing deleted tuples.
To clean (something) with a vacuum cleaner.
To use a vacuum cleaner.