| 释义 |
facultative, a.|ˈfækəlteɪtɪv|
[a. F. facultatif, -ive, f. L. facultātem: see faculty and -ative.]
1. a. Of enactments, etc.: Conveying a ‘faculty’ or permission; permissive as opposed to compulsory; hence of actions, conditions, etc.: Optional.
1820Ann. Reg. ii. 718 In forming these quotas, neither the facultative departmental centimes, nor the communal centimes shall be taken into account. 1839W. O. Manning Law of Nations v. vii. (1875) 387 Creating what is called ‘occasional’, ‘accidental’ or ‘facultative’ contraband. 1861M. Arnold Pop. Educ. France 50 What was..to use a French expression, facultative to the communes, what..they did or not as they liked. 1881Times 1 July 9/6 The great schools..treat classics as obligatory, and science as merely facultative. 1884Q. Rev. Apr. 403 Permit even for the Latin clergy a facultative celibacy.
b. transf. Used by scientific and philosophical writers for: That may or may not take place, or have a specified character.
1874Lewes Probl. Life & Mind I. 139 The Facultative Actions are those which..are..neither inevitably nor uniformly produced when the organs are stimulated, but..take sometimes one issue and sometimes another. 1875H. Walton Dis. Eye 621 The facultative [hypermetropia] is present when objects can be accurately seen at any distance. 1884Syd. Soc. Lex., Facultative hypermetropia..those cases of hypermetropia in which objects at an infinite distance can be distinctly seen both with and without convex glasses.
c. Biol. Not restricted to the particular function, mode of life, set of conditions, etc., implied in the context; opp. obligate ppl. a.
1887H. E. F. Garnsey tr. De Bary's Fungi vii. 356 Saprophytes..which have also the power of going through their course of development wholly or in part as parasites..may be called with Van Tieghem facultative parasites. 1900B. D. Jackson Gloss. Bot. Terms 98/1 Facultative, occasional, incidental, as opposed to obligate; ∼ Anaërobes, organisms which can exist without the presence of free oxygen or air. ∼ Symbiont, an organism which can either exist and reach maturity independently or in symbiosis with another. 1927Gwynne-Vaughan & Barnes Struct. & Devel. Fungi 13 A species which is usually saprophytic but capable of parasitic existence on occasion is described as a hemi-saprophyte or facultative parasite, and a form which is usually parasitic but sometimes saprophytic as a hemi-parasite or facultative saprophyte. 1935Discovery Jan. 27/2 The parasitic bacteria are a large and important group in which every stage of facultative and obligate parasitism can be found. 1940Chambers's Techn. Dict. 320/2 Facultative gamete, a zoospore which can function as a gamete. 1950J. G. Davis Dict. Dairying 13 The following table suggests terms for describing the reaction of micro-organisms to oxygen... Facultative anaerobe, Aerophilic..Facultative aerobe, Aerophobic. 1961Encounter XVI. 77 The ‘facultative homosexuals’..are those men who consider themselves heterosexually ‘normal’ but engage on occasion in some form of homosexual intercourse.
2. Of or proceeding from a faculty.
1866J. Martineau Ess. I. 154 Every facultative activity that goes out from me. 1888― Study Relig. I. i. i. 55 A purely inward process, viz. the play of an a priori facultative activity with the matter of our sensitive passivity.
Hence ˈfacultatively adv., in a facultative manner or degree, contingently.
1877Garnsey tr. De Bary's Fungi 360 Certain facultatively parasitic..species of Moulds. 1900[see aerobe]. 1914A. Harrison Kaiser's War 6 It [sc. military monarchism] has been set forth again and again by the German professors, politicians, and spokesmen, militarily, politically, and (as they say) facultatively. 1965Canad. Jrnl. Linguistics Spring 172 The qiˀ- allomorph of the future marker occurs facultatively before the yi- allomorph. |