also do-se-do, common step in square-, contra-, polka-dancing, etc., 1929, from French dos-à-dos "back to back" (see dossier).
"ancient upright monumental stone," very abundant in Brittany but also found in other places, 1834, from French menhir (19c.), from Breton, literally "long stone," from men "stone" + hir "long," from PIE *se-ro-, from root *se- "long, late" (see soiree). Cognate with Welsh maen hir, Cornish medn hir.
"diligent in application or pursuit of an object," 1530s, from Latin sedulus "attentive, painstaking, diligent, busy, zealous," probably from sedulo (adv.) "sincerely, diligently," from sedolo "without deception or guile," from se- "without, apart" (see se-) + dolo, ablative of dolus "deception, guile," which is cognate with Greek dolos "ruse, snare." Related: Sedulously; sedulousness.
also sea-side, "the land bordering on the sea, the margin or brim of the sea," c. 1200, from sea + side (n.). Especially in England, "the seacoast as a resort for pleasure or health," 1782; as an adjective in this sense from 1781. The meaning "the side facing the sea" seems to be late (19c.) and rare.
Other Middle English "seaside, seashore" words included sees koste (mid-14c.), sewarth (Old English sæwaroþ, from wār "seashore, beach"), se-ground, se-brimme, sæ-strand, sea-half (Old English sæhealf), se-bank (mid-14c.). Old English used særima "sea-rim," sæ-strande, etc.
"whooping cough," 1670s (Sydenham), from Modern Latin pertussis, from per- "thoroughly," or here perhaps with intensive force (see per), + tussis "cough," a word of unknown origin.