Greek words of this class used as adjectives mostly follow the same rule, as 'sporadic', 'dynamic', 'pneumatic', 'esoteric', 'philanthropic', 'emetic', 'panegyric'. As nouns the earlier introductions threw the stress back, as 'heretic', 'arithmetic', but later words follow the adjectives, as 'emetic', 'enclitic', 'panegyric'. As for 'politic', which is stressed as we stress both by Shakespeare and by Milton, it must be under French influence, though Skeat seems to think that it came straight from Latin.
Stems in -os. These words agree in being disyllabic, but otherwise they are a tiresome and quarrelsome people. For their diversity in spelling some can make a defence, since 'horror', 'pallor', 'stupor' came straight from Latin, but 'tenor', coming through French, should have joined hands with 'colour', 'honour', 'odour'. The short vowel is inevitable in 'horror' and 'pallor', the long in 'ardour', 'stupor', 'tumour'. The rest are at war, 'clamour', 'colour', 'honour', 'dolour', 'rigour', 'squalor', 'tenor', 'vigour' in the short legion, 'favour', 'labour', 'odour', 'vapour' in the long. Their camp-followers ending in -ous are under their discipline, so that, while 'clămorous', 'rĭgorous', 'vĭgorous' agree with the general rule, 'ōdorous' makes an exception to it. All the derivatives of favor are exceptions to the general rule, for 'favourite' and 'favorable' keep its long a. Of course 'lăbōrious' is quite in order, and so is 'văpid'.
Stems in -tor and -sor. These words, when they came through French, threw the stress back and shortened the penultimate, ōrātorem becoming orateur, and then 'ŏrător', with the stress on the antepenultimate. Others of the same type are 'auditor', 'competitor', 'senator', and Shelley has
The sister-pest, congrégator of slaves,
while 'amateur' is borrowed whole from French and stresses its ultima. Trisyllables of course shorten the first vowel, as 'crĕditor', 'jănitor'. Polysyllables follow the stress of the verbs; thus 'ágitate' gives 'ágitator' and 'compóse' gives 'compósitor'. To the first class belongs 'circulator', 'educator', 'imitator', 'moderator', 'negotiator', 'prevaricator', with which 'gladiator' associates itself; to the second belongs 'competitor'. Words which came straight from Latin keep the stress of the Latin nominative, as 'creator', 'spectator', 'testator', 'coadjutor', 'assessor', to which in Walton's honour must be added 'Piscator' and 'Venator'. On 'curator' he who decides does so at his peril. On one occasion Eldon from the Bench corrected Erskine for saying 'cúrător'. 'Curātor, Mr. Erskine, curātor.' 'I am glad', was the reply, 'to be set right by so eminent a senātor and so eloquent an orātor as your Lordship.' Neither eminent lawyer knew much about it, but each was so far right that he stuck to the custom of his country. On other grounds Erskine might be thought to have committed himself to 'téstător', if not quite to the 'testy tricks' of Sally in Mrs. Gaskell's 'Ruth'.
Stems in -ero and -uro. Adjectives of this type keep the Latin stress, which thus falls on the ultima, and shorten or obscure the penultimate vowel, as 'mature', 'obscure', 'severe', 'sincere', but of course 'āustere'. Of like form though of other origin is 'secure'. Nouns take an early stress, as 'áperture', 'sépulture', 'líterature', 'témperature', unless two mutes obstruct, as in 'conjécture'. Of the disyllables 'nature' keeps a long penultima, while 'figure' has it short, not because of the Latin quantity, but because of the French.
The lonely word 'mediocre' lengthens its first vowel by the 'alias' rule and also stresses it. Whether the penultima has more than a secondary stress is a matter of dispute.
Stems in -ari. These words have the stress on the antepenultima, which they shorten, as in 'secular' or keep short as in 'jocular', 'familiar', but of course 'pecūliar'.
On certain Greek words.
It will have been seen that Greek words are usually treated as Latin. Thus 'crisis' lengthens the penultima under the 'apex' rule, while 'critical' has it short under the general rule of polysyllables. Other examples of lengthening are 'bathos', 'pathos', while the long quantity is of course kept in 'colon' and 'crasis'. For the 'alias' rule we may quote 'ātheist', 'cryptogāmia', 'hōmeopathy', 'heterogēneous', 'pandemōnium', while the normal shortenings are found in 'anŏnymous', 'ephĕmeral', 'pandĕmonium', 'ĕrĕmite'. Ignorance of English usage has made some editors flounder on a line of Pope's: