phe·nom·e·non (f?-n?m??-n?n?, -n?n)n. pl. phe·nom·e·na (-n?) 1. An occurrence, circumstance, or fact that is perceptible by the senses.2. pl. phe·nom·e·nons a. An unusual, significant, or unaccountable fact or occurrence; a marvel.b. A remarkable or outstanding person; a paragon. See Synonyms at wonder.3. Philosophy In the philosophy of Kant, an object as it is perceived by the senses, as opposed to a noumenon.4. Physics An observable event.[Late Latin phaenomenon, from Greek phainomenon, from neuter present participle of phainesthai, to appear; see bh?- in Indo-European roots.]Usage Note: Phenomenon is the only acceptable singular form of this noun; phenomena is the usual plural. Phenomenons may also be used as the plural in nonscientific writing when the meaning is “extraordinary things, occurrences, or persons”: They were phenomenons in the history of music.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.phenomenon (f??n?m?n?n) n, pl -ena (-?n?) or -enons1. anything that can be perceived as an occurrence or fact by the senses2. any remarkable occurrence or person3. (Philosophy) philosophy a. the object of perception, experience, etcb. (in the writings of Kant) a thing as it appears and is interpreted in perception and reflection, as distinguished from its real nature as a thing-in-itself. Compare noumenon[C16: via Late Latin from Greek phainomenon, from phainesthai to appear, from phainein to show]Usage: Although phenomena is often treated as if it were singular, correct usage is to employ phenomenon with a singular construction and phenomena with a plural: that is an interesting phenomenon (not phenomena); several new phenomena were recorded in his notesCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014phe?nom?e?non (f??n?m ??n?n, -n?n) n., pl. -na (-n?) or, esp. for 3, -nons. 1. a fact, occurrence, or circumstance observed or observable: the phenomena of nature. 2. something that is remarkable or extraordinary. 3. a remarkable or exceptional person; prodigy. 4. Philos. a. an appearance or immediate object of awareness in experience. b. (in Kantian philosophy) a thing as it appears to and is constructed by the mind, as distinguished from a noumenon, or thing-in-itself. [1595?1605; A phenomenon is something that happens or exists and that can be seen or experienced.The plural of ‘phenomenon’ is phenomena, not ‘phenomenons’.Be Careful!Phenomena is only a plural form. You do not talk about ‘a phenomena’ or ‘this phenomena’.