English Reference
adjective · noun

optimal

adj. · n.
US /ˈɑptəməɫ/ UK /ˈɒptɪməl/ op·ti·mal

  1. 01 B2 Upper Intermediate Academic

    adj.the best or most effective possible in a particular situation.

    adj.the most favourable or desirable condition or outcome, especially when considering specific constraints or requirements.

    Simple

    The plants need an optimal amount of sunlight and water to grow quickly.

    In context

    To achieve optimal performance, the engine must be maintained at a specific temperature range throughout the duration of the flight.

    Usage

    This adjective is non-gradable; something is either optimal or it is not, so avoid saying 'more optimal'.

    suboptimalworst
  2. 02 C1 Advanced TechnicalAcademic Science

    n.the best possible level or state that can be reached.

    n.the best or most favourable degree, quantity, or condition for a particular result.

    Simple

    The experiment reached its optimal after three hours of heating.

    In context

    The research team sought to identify the mathematical optimal for fuel efficiency across various atmospheric pressures.

    Usage

    Often used interchangeably with 'optimum' in technical contexts.

Usage concurrent optimal · optimal choice · optimal combination

The results were clear: In groups without AI, the optimal strategy was almost never discovered.

Phys.org· 18 Aug 2026

A theory dating back more than 100 years suggested that there is an optimal amount of stress for good performance, based on a study that had nothing to do with humans.

The Conversation· 31 Jul 2026

From Latin optimus + -al.

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

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated