English Reference
adjective · noun

functional

adj. · n.
US /ˈfəŋkʃənəɫ/ UK /fˈʌŋkʃənəl/ func·tion·al UK spelling functionals

  1. 01 B2 Upper Intermediate

    adj.working correctly and ready to use.

    adj.in good working order; operational and performing its intended task.

    Simple

    The elevator is finally functional again after being broken for a week.

    In context

    Engineers worked through the night to ensure the cooling system was fully functional before the reactor was brought back online.

  2. 02 B2 Upper Intermediate

    adj.designed to be useful and practical rather than just attractive.

    adj.designed for utility and purpose rather than aesthetic appeal.

    Simple

    The furniture in the office is functional but not very comfortable.

    In context

    The architect prioritised a functional layout that facilitated easy movement between departments over more decorative, traditional design elements.

  3. 03 C1 Advanced Academic

    adj.relating to the specific job or purpose someone or something has.

    adj.relating to a specific function, role, or office.

    Simple

    The manager has a functional responsibility to oversee the budget.

    In context

    The restructuring aimed to clarify functional boundaries between the research and development teams to prevent overlapping duties.

  4. 04 C2 Proficiency Technical Medicine

    adj.used to describe health problems that affect how the body works but do not show physical damage.

    adj.referring to symptoms or disorders that affect physiological performance without an apparent organic or structural cause.

    Simple

    The doctor explained that his stomach pain was a functional disorder caused by stress.

    In context

    Functional neurological disorders can present with significant motor impairment despite the absence of visible lesions on a standard MRI scan.

  5. 05 C1 Advanced Technical Computing

    adj.a way of writing computer code based on mathematical functions.

    adj.relating to a programming paradigm that treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data.

    Simple

    Functional programming languages like Haskell are popular for complex data analysis.

    In context

    The team decided to adopt a functional approach for the new microservice to minimize side effects and improve code testability.

  6. 06 C2 Proficiency Technical Math

    n.a special type of mathematical rule that takes a function as its input.

    n.a function whose domain is a set of functions and whose range is a set of scalars.

    Simple

    In his advanced math class, he learned how to calculate a linear functional.

    In context

    The researcher defined a functional that mapped each continuous path to its total energy consumption over a fixed interval.

Usage appreciation functional · functional analysis · functional approach

Variation in the beetle's body shape is caused by a functional trade-off between two feeding strategies.

Phys.org· 17 Aug 2026

But if these were families, they were frequently barely functional ones, without much staying power.

The Guardian· 11 Aug 2026

From function + -al.

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

This entry
Level C1 · Advanced
Frequency Common
Updated