utmost

Etymology

PIE word *úd From Middle English utmost, utemest [and other forms], from Old English ūtmest, ūtemest [and other forms], from ūt, ūte (“out; outdoors, outside”) + -mest (suffix meaning ‘furthest’, used to form superlatives of some adjectives) (and conflated with most). Ūt is derived from Proto-Germanic *ūt (“out, outward”), from Proto-Indo-European *úd (“out, outward”).

adj

1. Situated at the most distant limit; farthest, outermost.
   the utmost limits of the land
   the utmost extent of human knowledge
   [T]he maſters, wardens, ſearchers, aſſiſtants and commonalty of the company of cutlers in Hallamſhire in the county of York, their ſucceſſors and aſſigns, are nominated and appointed undertakers of the ſaid navigation, with power to make the ſaid river navigable, at their own expence, from Holmſtile aforeſaid, up the ſaid river above Holmſtile to the utmoſt extent of Tinſley westward, … 1733, Danby Pickering, “Cap. IX. An Act to Explain and Amend Two Acts of Parliament,[…], for Making Navigable the River Dun in the County of York,[…]”, in The Statutes at Large, from the Second to the 9th Year of King George II.[…], volume XVI, Cambridge, Cambridgeshire: […] Joseph Bentham,[…]; for Charles Bathurst,[…], published 1765, →OCLC, page 370
   As yet we are far from having explored the utmost depths of space. Our telescopes have only reached a limited distance into the regions of the heavens. 1852 March, Professor Larrabee, “The Heavens”, in W. C. Larrabee, editor, The Ladies’ Repository: A Monthly Periodical, Devoted to Literature and Religion, volume XII, Cincinnati, Oh.: L. Swormstedt and A. Poe; […], →OCLC, page 109, column 1
   Our nature is need for truth and fulfilment, or, in other words, happiness. … But this desire, having reached the extreme borders of our life experience, still does not find what it has been searching for: at the utmost frontier of its lived territory, this urgent need of ours still has not found its answer. 1997, Luigi Giussani, “The Hypothesis of Revelation: Conditions for Its Acceptability”, in John Zucchi, transl., The Religious Sense, Montreal, Que.: McGill–Queen's University Press, page 141
2. The most extreme; greatest, ultimate.
   the utmost assiduity
   the utmost harmony
   the utmost misery or happiness
   She was a lady adorned with many noble virtues: the utmoſt ſtrictneſs in her life and morals, eaſy and affable in her behaviour, and agreeably modeſt in her converſation. 1752, Jerome Osorio [i.e., Jerónimo Osório], “Book XI”, in James Gibbs, transl., The History of the Portuguese, during the Reign of Emmanuel:[…], volume II, London: […] A[ndrew] Millar,[…], →OCLC, page 239
   The migrations of the Economic Rats, are not less extraordinary than those of the Lemmings. In the spring of the year they collect together in amazing numbers, and proceed in a course directly westward; swimming with the utmost intrepidity over rivers, lakes, and even arms of the sea. 1824, W[illiam] Bingley, Animal Biography, or, Popular Zoology;[…], 6th edition, volumes II (Mammiferous Animals—Birds), London: […] C[harles] and J[ohn] Rivington; …, →OCLC, pages 26–27
   A contract of marine insurance is uberrimae fidel or, as enunciated in s 17 of the Marine Insurance Act, 'a contract based upon the utmost good faith'. … The obligations to disclose and to abstain from misrepresentations constitute the most significant manifestations of the duty to observe utmost good faith. 1999, Susan Hodges, Roy Carlile, “Utmost Good Faith, Disclosure and Representations”, in Cases and Materials on Marine Insurance Law, London: Cavendish Publishing, page 213
   Of course, everything was of utmost importance to Isabel Trent, Miriam thought with a sigh. Nevertheless she adopted her expression of utmost gravity as she replied, "Oh? I'm all ears." 2001, Elizabeth Bevarly, “The Temptation of Rory Monahan”, in Katherine Garbera, Elizabeth Bevarly, An Irresistible Temptation (Harlequin Man of the Month), Don Mills, Ont.: Harlequin Enterprises, published 2015, chapter 1, page 184
   Indeed at this very moment he's slipped away with the utmost cunning into a form that's most perplexing to investigate. 2005, Plato, translated by Lesley Brown, Sophist, page 236d

noun

1. The greatest possible capability, extent, or quantity; maximum.
   at the utmost    to the utmost
   [T]he utmoſt they could do, was to perſuade Him to lay aſide all Rancor and Diſcontent againſt thoſe Confederate Lords, and to hearken to their deſires. 1704, James Tyrrell, “Book XII. Containing the Reign of King Richard II.”, in The General History of England, both Ecclesiastical and Civil:[…], volume III, 2nd part, London: […] W. Rogers,[…]; J. Taylor,[…]; J. Sprint,[…]; and A[ndrew] Bell,[…], →OCLC, page 912
   We drank martinis, while she gazed into my eyes and talked of Dolores – in tones of the utmost loathing – and of you, in tones of the utmost self-importance. 2011, Simone de Beauvoir, “January 1947 – October 1951: America”, in Quintin Hoare, transl., Letters to Sartre, New York, N.Y.: Arcade Publishing, page 415