Residue

• Residue (chemistry), material remaining after a distillation or an evaporation, or portion of a larger molecule
• Residue (law), portion of the testator's estate that is not specifically devised to someone in the will
• Residue (complex analysis), mathematics, complex number describing the behavior of line integrals of a meromorphic function around a singularity
• Crop residue, materials left after agricultural processes

Residue may also be:

• The remainder in modular arithmetic
• The heavier fractions of crude oil that fail to vaporize in an oil refinery