English Reference
adjective · noun

residual

adj. · n.
US /ɹɪˈzɪdʒuəɫ/ UK /ɹɪsˈɪdʒuːəl/ resid·u·al UK spelling residuals

  1. 01 C1 Advanced Academic

    adj.remaining after the main part of something has gone or been taken away.

    adj.relating to or constituting a residue; remaining after the majority of a substance or quantity has been removed or processed.

    Simple

    Even after cleaning the engine, there was some residual oil on the floor.

    In context

    The laboratory results indicated a small amount of residual pesticide in the soil samples, despite the field not being treated for several years.

    Usage

    Usually placed before the noun it modifies.

  2. 02 C1 Advanced Technical Science

    n.a small amount of something that remains after a process is finished.

    n.a quantity or substance remaining after a specific process, such as evaporation or combustion, has been completed.

    Simple

    The chemist analyzed the residual left in the bottom of the flask.

    In context

    The industrial process was designed to minimize the toxic residuals that often accumulate during the cooling phase.

  3. 03 C1 Advanced Technical

    n.money paid to actors or writers when their show or movie is shown again.

    n.payments made to creative professionals, such as performers or directors, for the subsequent broadcast or sale of a recorded work.

    Simple

    The actor still receives residuals every time the old sitcom airs on TV.

    In context

    The union negotiated a new contract to ensure that writers receive fair residuals from streaming platforms as well as traditional broadcast networks.

    Usage

    Almost always used in the plural form 'residuals'.

  4. 04 C2 Proficiency AcademicTechnical Math

    n.the difference between a real measurement and what a mathematical model predicted.

    n.the difference between an observed value and the value predicted by a statistical model or regression line.

    Simple

    The researcher checked the residuals to see if the model was accurate.

    In context

    A pattern in the residuals suggested that the linear model was inappropriate for the dataset and required a non-linear approach.

  5. 05 C2 Proficiency Informal

    n.a feeling or energy left in a place after a big event or a person's death.

    n.a spiritual or energetic trace allegedly left in a location following a significant or traumatic event.

    Simple

    Some people believe the cold spot in the hallway is a residual from the house's history.

    In context

    Paranormal investigators often distinguish between an intelligent haunting and a mere residual that repeats like a recording.

The review also found evidence of residual effects lasting up to 24 hours.

BBC News· 15 Aug 2026

Researchers have now detected that residual signal for the first time, finding it closely matched predictions of radioactive decay inside the reactor and nearby spent-fuel pools.

ScienceDaily· 14 Aug 2026

Recorded since 1570. From residue, itself borrowed during the Middle English period from Old French residu (Modern French résidu), from Latin residuum (“a remainder”), the neuter inflection of residuus (“remaining, left over”), perfect participle of resideō (“to remain behind”), from re- (“back, again”) + sedeō (“to sit, to reside”).

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

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