英语词源字典 - 在线词源网站

doctor [doctor 词源字典]: doctor: [14] Doctor, doctrine, and document all go back ultimately to the Latin verb docēre ‘teach’. This in turn was a descendant of an Indo-European base *dok-, *dek- which also produced Greek dokein ‘seem, think’ (source of English dogma [17], orthodox, and paradox) and didáskein ‘learn’ (source of English didactic [17]) and Latin decere ‘be fitting or suitable’ (source of English decent, decorate, and dignity) and dexter (source of English dextrous).

Latin doctor was derived from doctus, the past participle of docēre, and came into English via Old French doctour. It originally meant ‘teacher’, and the main modern sense of ‘medical practitioner’, although sporadically recorded in Middle English, did not become firmly established until the late 16th century. Latin doctrīna ‘teaching, learning’, a derivative of Latin doctor, produced English doctrine [14].

Latin documentum, which came directly from docēre, originally meant ‘lesson’, but in medieval Latin its signification had passed through ‘written instruction’ to ‘official paper’. English acquired it as document [15]. The derivative documentary is 19th-century.
=> dainty, decent, decorate, dextrous, didactic, dignity, doctrine, document, dogma, orthodox, paradox[doctor etymology, doctor origin, 英语词源]
R: In a circle, meaning "registered (trademark)," first incorporated in U.S. statues 1946. R&R "rest and relaxation," first recorded 1953, American English; R&B "rhythm and blues" (type of popular music) first attested 1949, American English.
If all our r's that are written are pronounced, the sound is more common than any other in English utterance (over seven per cent.); the instances of occurrence before a vowel, and so of universal pronunciation, are only half as frequent. There are localities where the normal vibration of the tip of the tongue is replaced by one of the uvula, making a guttural trill, which is still more entitled to the name of "dog's letter" than is the ordinary r; such are considerable parts of France and Germany; the sound appears to occur only sporadically in English pronunciation. [Century Dictionary]

The moment we encounter the added r's of purp or dorg in our reading we know that we have to do with humor, and so with school-marm. The added consonants are supposed to be spoken, if the words are uttered, but, as a matter of fact, they are less often uttered than seen. The words are, indeed, largely visual forms; the humor is chiefly for the eye. [Louise Pound, "The Humorous 'R,'" "American Mercury," October 1924]
She goes on to note that in British humorous writing, -ar "popularly indicates the sound of the vowel in father" and formations like larf (for laugh) "are to be read with the broad vowel but no uttered r." She also quotes Henry James on the characteristic prominence of the medial -r- sound (which tends to be dropped in England and New England) in the speech of the U.S. Midwest, "under some strange impulse received toward consonantal recovery of balance, making it present even in words from which it is absent, bringing it in everywhere as with the small vulgar effect of a sort of morose grinding of the back teeth."
sporadic (adj.): 1680s, from Medieval Latin sporadicus "scattered," from Greek sporadikos "scattered," from sporas (genitive sporados) "scattered, dispersed," from spora "a sowing" (see spore). Originally a medical term, "occurring in scattered instances;" the meaning "happening at intervals" is first recorded 1847. Related: Sporadical (1650s); sporadically.
-ville: suffix sporadically in vogue since c. 1840 in U.S. colloquial word formation (such as dullsville, palookaville), abstracted from the -ville in place names (Louisville, Greenville, etc.), from Old French ville "town," from Latin villa (see villa).