undercurrent

Etymology

under- + current.

noun

1. A current of water which flows under the surface, and often in a different direction from surface currents.
   For that an undercurrent (which ſome have beleived,) in the ſtraights-mouth, will not ſolve this difficulty, unleſs occaſioned by a vaſt Gulf that muſt be placed ſomewhere in the Atlantic near the Mouth of the ſtraight, which though overflown and hidden by that mighty ſea, yet may poſſibly abſorb the deeper waters, and ſo cauſe a contrary undercurrent. 1684–1685 January 28, “De ORIGINE FONTIUM Tentamen Philosophicum, in Prælectione habita coram Societate Philosophica nuper Oxoniæ instituta ad Scientiam Naturalem promovendam. Per Rob. Plot LL.D. Custodiæ MUSÆI ASHMOLEANI Oxoniæ Præpositum. & REGIÆ SOCIETATIS Secretarium Oxon. in 8º. 1685. [A Philosophical Essay on the ORIGIN OF THE SPRINGS, in Lectures Given before the Philosophical Society lately Instituted in Oxford to Promote Natural Science. By Rob[ert] Plot LL.D., Appointed Keeper of the ASHMOLEAN MUSEUM, & Oxford Secretary of the ROYAL SOCIETY. In Octavo. 1685.]”, in Philosophical Transactions, Giving Some Accompt of the Present Undertakings, Studies, and Labours, of the Ingenious, in Many Considerable Parts of the World, volume XV, number 167, Oxford: Printed at the Theater, and are to be sold by Samuel Smith,[…]; and Henry Clements,[…], published 1686, →OCLC, page 864
   [W]e have a surface current of saltish water from the poles towards the equator, and an undercurrent of water, saltier and heavier, from the equator to the poles. This undercurrent supplies in a great measure the salt which the upper current, freighted with fresh water from the clouds and rivers, carries back. 1854 January, M[atthew] F[ontaine] Maury, “[On the Saltiness of the Sea]”, in Explanations and Sailing Directions to Accompany the Wind and Current Charts,[…], 6th enlarged and improved edition, Philadelphia, Pa.: E. C. and J. Biddle,[…], →OCLC, page 183
2. (figurative) A tendency of feeling or opinion that is concealed rather than exposed.
   The meeting was pervaded with an undercurrent of dread, as the managers tried not to admit that firings were looming.
   Voltaire showed little respect for any conventionality which did not command his acquiescence; yet it may be doubted whether an undercurrent of affectation does not more or less mar the effect of everything he has written. 1876 April, “Art. I.—Jonathan Swift. The Life of Jonathan Swift. By John Forster, Vol. I. London: John Murray.”, in The British Quarterly Review, American edition, volume LXIII, New York, N.Y.: Published by the Leonard Scott Publishing Company,[…], →OCLC, page 150, column 1
   A vaguely defined genre (as the name announces, it was first noticed by the French), Film Noir is one of the more complex and intelligent Hollywood styles. Part detective story, part gangster, part urban melodrama, Film Noir was identified best by its dark and pessimistic undercurrents. 1977, James Monaco, “The Shape of Film History”, in How to Read a Film: The Art, Technology, Language, History, and Theory of Film and Media, New York, N.Y.: Oxford University Press, →OCLC, page 251
   Although the crowd was predominantly red-and-white, there was also a Romanian flavour, which these days in football terms tends to mean there is at least an undercurrent of discontent. 9 May 2012, Jonathan Wilson, “Europa League: Radamel Falcao’s Atlético Madrid rout Athletic Bilbao”, in The Guardian, London, archived from the original on 2018-04-25
   The feminist undercurrents of Fury Road got a lot of ink when the movie came out; critics loved pointing out that [George] Miller had brought in The Vagina Monologues writer Eve Ensler as an on-set consultant. 1 December 2017, Tom Breihan, “Mad Max: Fury Road Might Already be the Best Action Movie Ever Made”, in The A.V. Club, archived from the original on 2018-02-22

verb

1. (transitive, also figurative) To flow under some surface.
   The latter are stoically steady, impervious to the nervousness that still continues to undercurrent the Stock Exchange generally, despite an all-round rally. 1905, The Electrical Review, volume 56, London: H. Alabaster, Gatehouse & Company, →OCLC, page 154
   Her lips hardly moving, every feature steady, she undercurrented my narrative with ejaculations in French, Russian, Italian. 1927, The Atlantic Monthly. A Magazine of Literature, Science, Art, and Politics, volume 139, Boston, Mass.: Ticknor and Fields,[…], →OCLC, page 627, column 2
   The emotions undercurrenting the command left her with no doubt that he planned to do as he said. 1996, Jane Lindskold, Smoke and Mirrors, New York, N.Y.: Avon Books
   Mining-wights could be heard at work in the walls, sometimes undercurrented by the drone and whirr of eldritch spinning wheels. 2005, Cecilia Dart-Thornton, The Well of Tears (The Crowthistle Chronicles; 2), Sydney, N.S.W.: Tor Books, Pan Macmillan Australia; paperback edition, London: Tor, Pan Macmillan, 2006, page 367