English Reference
noun

residue

n.
US /ˈɹɛzəˌdu/ UK /ɹˈɛsɪdjˌuː/ residue UK spelling residue's, residue's

  1. 01 C1 Advanced Technical Science

    a small amount of something that stays on a surface after the rest has been removed.

    the material or substance that remains after a process such as evaporation, combustion, or filtration.

    Simple

    The sticker left a sticky residue on the window that was hard to clean.

    In context

    The laboratory analysis detected a chemical residue on the surface of the fruit, suggesting that pesticides had been applied shortly before harvest.

    Usage

    Often used as an uncountable noun when referring to a layer of material.

  2. 02 C1 Advanced FormalTechnical Law

    the part of a person's money or property that is left after all debts and specific gifts are paid.

    the portion of a testator's estate remaining after the payment of debts, funeral expenses, and specific legacies.

    Simple

    After the house was sold and the bills were paid, the residue of the money went to charity.

    In context

    The will stipulated that the residue of the estate should be divided equally among the deceased's three grandchildren after all specific bequests were fulfilled.

    Usage

    Typically used in the context of wills and probate law.

  3. 03 C2 Proficiency Technical Math

    the number that is left over after one number is divided by another.

    a representative element of an equivalence class; the remainder left after a division operation in modular arithmetic.

    Simple

    In this calculation, we need to find the residue of seventeen modulo five.

    In context

    The student struggled to calculate the quadratic residue, a fundamental concept in advanced number theory and cryptography.

  4. 04 C2 Proficiency Technical Science

    a single part of a larger molecule, like one link in a chain.

    a specific unit within a polymer, such as a single amino acid within a protein chain.

    Simple

    The protein is made of a long string of amino acid residues.

    In context

    The researchers identified a specific cysteine residue that was essential for the enzyme's catalytic activity.

Family members or other close contacts can be exposed when they encounter residue on farmworkers’ skin and clothing.

Ars Technica· 18 Aug 2026

For centuries, farmers had sustained soil fertility by recycling locally available nutrients , including animal manure, crop residues and human waste.

The Conversation· 27 Jul 2026

From Middle English residue, from Old French residu, from Latin residuum, neuter of residuus (“remaining”), from resideō (“I remain behind”). Doublet of residuum.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin residuum
Level C1 · Advanced
Frequency Frequent
Updated