func tionalとは 意味・読み方・使い方

発音

• IPA: /ˈfʌŋkt͡ʃənəl/, /ˈfʌŋkt͡ʃnəl/

形容詞

functional (comparative more functional, superlative most functional)

1. In good working order.
   • 2002, Ludo Verhoeven, Carsten Elbro, Pieter Reitsma, editors, Precursors of Functional Literacy‎:

     While we assume that phonological subsyllabic units are functional prior to reading skill, we have not ruled out a possible interaction with the writing system.

2. Useful; serving a purpose, fulfilling a function.

   That sculpture is not merely artistic, but also functional: it can be used as a hatrack.

   • 2013 July 3, Jacque Wilson, “‘Functional fitness’ keeps seniors moving”, in CNN‎:

     The two are often one and the same, says Walt Thompson, professor of kinesiology at Georgia State University and lead author of the ACSM survey – although functional fitness can apply to the younger generation as well.

3. Only for functional purposes, notably in architecture.

   A functional construction element generally must meet higher technical but lower aesthetical requirements.

4. Of or relating to one's role or office; official.

   functional responsibilities

5. (physiology, psychology) Characterizing functioning in environment, being symptoms that do not presuppose alteration of organic structure.
   • 1928 December 15, Frank J. Hirschboeck, “Treatment of Functional Heart Disease”, in The Journal of the American Medical Association‎, volume 91, number 24, →DOI, page 1852:

     The clinical differentiation between functional and organic disease is at times difficult to establish, because, presumptively, in the beginning, at least, all organic disease is preceded by a physiologic perversion, that is, functional alteration, which may or may not be apparent with our present diagnostic limitations. […] Though benign rhythmic disturbances, such as premature contractions or paroxysmal tachycardia, do occur, it is notoriously difficult and still the subject of argument whether these may be called functionally benign or whether they may prove to have organic significance. […] The lack of opportunity for the medical student to observe the functional states in the medical school clinics and hospital practice, because of lack of space, or interest in their care in intramural teaching, is, I believe, a most forceful argument for a period of extramural practice under intelligent tutelage.

   • 2025 August 13, Müjdat Erarkadaş, Kübra Özmeral Erarkadaş, Şahika Gülen Şişmanlar, “Autism Spectrum Disorder Beyond Childhood: A Comprehensive Assessment of Activities of Daily Living and Social Functioning in Turkish Adults”, in Journal of Autism and Developmental Disorders‎, →DOI:

     In our study of participants aged 18–39, increasing age was associated with improved functioning in laundry task and overall social functioning, encompassing prosocial activities, recreation, independence–competence, and employment. […] However, several longitudinal and cross-sectional studies indicate that these improvements tend to plateau by the late twenties, and may decline as individuals transition into middle adulthood (Clarke et al., 2021; Smith et al., 2012; Tomaszewski et al., 2025). These patterns suggest that while functional gains may be observed through early adulthood, they may not be maintained beyond the early thirties. Therefore, longitudinal studies extending into middle and late adulthood are critically needed to clarify how trajectories of activities of daily living and social functioning evolve throughout the lifespan.

6. Optimized for all-around physiological benefit.

   functional coffee

   functional fitness

7. (mathematics) Of or relating to a function or functions.
8. (computing theory) Having semantics defined purely in terms of mathematical functions, without side-effects.

   Synonym: pure

   Antonym: imperative

同意語

• functioning, working
• utilitarian

反意語

• dysfunctional
• non-functional, nonfunctional, unfunctional
• (antonym(s) of “medicine: not referrable to a change of structure”): organic

下位語

派生語

関連する語

名詞

functional (plural functionals)

1. (mathematics) A function that takes a function as its argument; more precisely, a function whose argument varies in a space of (real- or complex-valued) functions and whose value belongs to a monodimensional space.

   An example of a functional is the definite integration of integrable real functions in a real interval.

2. (mathematics, functional analysis) A scalar-valued linear function on a vector space.
3. (computing) An object encapsulating a function pointer (or equivalent).

派生語

• functional analysis
• functional analysis diagram
• linear functional

参照

• functional on Wikipedia.Wikipedia

Further reading

• “functional”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “functional”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.
• “functional”, in OneLook Dictionary Search.