The Collaborative International Dictionary of English v.0.48:

Everyday \Ev"er*y*day`\, a.
   Used or fit for every day; common; usual; as, an everyday
   suit of clothes.
   [1913 Webster]

         The mechanical drudgery of his everyday employment.
                                                  --Sir. J.
                                                  Herchel.
   [1913 Webster]

WordNet (r) 3.0 (2006):

everyday
    adj 1: found in the ordinary course of events; "a placid
           everyday scene"; "it was a routine day"; "there's nothing
           quite like a real...train conductor to add color to a
           quotidian commute"- Anita Diamant [syn: everyday,
           mundane, quotidian, routine, unremarkable,
           workaday]
    2: appropriate for ordinary or routine occasions; "casual
       clothes"; "everyday clothes" [syn: casual, everyday,
       daily]
    3: commonplace and ordinary; "the familiar everyday world"

Moby Thesaurus II by Grady Ward, 1.0:

90 Moby Thesaurus words for "everyday":
   Attic, accepted, accustomed, average, chaste, circadian, classic,
   classical, colloquial, common, commonplace, conformable,
   consuetudinary, conventional, conversational, current, customary,
   daily, diurnal, dull, established, familiar, frequent,
   frequentative, garden, garden-variety, generally accepted,
   habitual, homely, homespun, household, inferior, informal, lowly,
   many, many times, matter-of-fact, mediocre, mundane, nondescript,
   nonstandard, normal, normative, not rare, obtaining,
   of common occurrence, oft-repeated, oftentime, ordinary, plain,
   popular, predominating, prescribed, prescriptive, prevailing,
   prevalent, prosaic, prosy, pure, pure and simple, quotidian,
   received, recurrent, regular, regulation, routine, run-of-the-mill,
   set, simple, spoken, standard, stock, substandard, thick-coming,
   time-honored, traditional, uneducated, unexceptional, unexciting,
   unimaginative, universal, unliterary, unremarkable, unstudied,
   usual, vernacular, widespread, wonted, workaday, workday