contribution to the lexicography of the term
The Oxford English Dictionary indicates that the word 'Utilitarianism' first occured in 1827 in George S. Faber, The Sacred Calendar of Prophecy, 3 vols, London (later eds. 1843, 1844), i. 202: 'Intent only upon the present, ... men will ... devote themselves ... to a life ... of sordid godless Utilitarianism.'
Professor Professor J. H. Burns (Emeritus Professor of History, UCL and a past director of the Bentham Project) notes a later occurrence in J. W. Semple's (d. 1844) translation of Kant's Metaphysics of Ethics (Edinburgh 1836; later edns Edinburgh, 1869, 1871) where the term is used on p. 144 'To distinguish between utilitarianism and morality ...'
Professor Burns thinks this to be significant for the lexicography of the term 'utilitarianism'. He points out that the existing OED references seem not 'to refer to utilitarianism as a doctrine or system of ideas.' He further comments that 'JS Mill used the word in a letter to Carlyle on 12 January 1834; but as far as I can see he does not use the -ism form in his published writings until the 1861 essay (Utilitarianism. ii. 16).
Semple has no entry in the Oxford Dictionary of National Biography but Professor Burns hopes to rescue him from obscurity in the course of research into the Scottish Kantians.