"send by post," 1828, American English, from mail (n.1). "The usual word in the U.K. is still post" [OED]. Related: Mailed; mailing; mailable. Mailing list "register of addresses" is attested from 1876.
American English shortening of mathematics, 1890; the British preference, maths, is attested from 1911. "Math. is used as an abbreviation in written English in the U.K. but not in speech, the normal form being Maths" [OED].
"above or beyond the proper amount or degree," mid-15c., from over (adv.) + -ly. Old English had oferlice "excessively." Used colloquially in place of over- in certain situations. After Old English and until 20c., the word is mostly in Scottish and American English and was often "regarded as an Americanism in the U.K." [OED].
"one who travels about selling small wares which he carries with him," late 14c., pedelere (c. 1300 as a surname, Will. Le Pedelare), altered from peoddere, peddere (c. 1200, mid-12c. as a surname), which probably is from Medieval Latin pedarius "one who goes on foot" [The Middle English Compendium], from Latin pes (genitive pedis) "foot," from PIE root *ped- "foot." Middle English ped "panier, wicker basket" is a back-formation from pedder. Pedlar, preferred spelling in U.K., is attested from late 14c.
1965, apparently coined by U.K. politician Iain Macleod (1913-1970), from stag(nation) + (in)flation.
Attacking the Government's economic policy last night in the House of Commons, Mr. Iain Macleod (West Enfield - Con.) the Opposition spokesman on Treasury and economic affairs, described the present situation in Britain as "stagflation" — stagnation and inflation together. [Glasgow Herald, Nov. 18, 1965]