(topology) A theorem which (in one of its simplest forms) states that a continuous function from an n-dimensional unit cube (in ℝⁿ) to itself has a fixed point.

(mathematics) A formula that counts the fixed points of a continuous mapping from a compact topological space X to itself by means of traces of the induced mappings on the homology groups of X.

It is often fruitless to help people that are stupid and do stupid things.

(proverbial) To deal with a problem or potential problem while conditions are favorable.

The act of fixing. / The state of being fixed or fixated. / The act of uniting chemically with a solid substance or in a solid form; reduction to a non-volatile condition; -- said of volatile elements.

(chemistry, biochemistry) the conversion of atmospheric nitrogen into ammonia and organic derivatives, by natural means, especially such conversion, by microorganisms in the soil, into a form that can be assimilated by plants

(US, informal) A house, property, car, or other object that needs to be fixed up or repaired, often purchased as an investment.

(law) Something that is fixed in place, especially a permanent appliance or other item of personal property that is considered part of a house and is sold with it; compare fitting, furnishing.

(transitive) To furnish with, as, or in a fixture. / (transitive, sports, Australia, New Zealand) To schedule (a match).

Agent noun of fix; one who, or that which, fixes. / (photography) A chemical (sodium thiosulfate) used in photographic development that fixes the image in place, preventing further chemical reactions.