[1] : The Collaborative International Dictionary of English v.0.48

erratic \errat"ic\, a. l. erraticus, fr. errare to wander: cf.
   f. erratique. see err.
   1. having no certain course; roving about without a fixed
      destination; wandering; moving; -- hence, applied to the
      planets as distinguished from the fixed stars.
      1913 webster

            the earth and each erratic world.     --blackmore.
      1913 webster

   2. deviating from a wise of the common course in opinion or
      conduct; eccentric; strange; queer; as, erratic conduct.
      1913 webster

   3. irregular; changeable. "erratic fever." --harvey.
      1913 webster

   erratic blocks, gravel, etc. geol., masses of stone
      which have been transported from their original resting
      places by the agency of water, ice, or other causes.

   erratic phenomena, the phenomena which relate to
      transported materials on the earth's surface.
      1913 webster
see also:
err erratic blocks gravel, etc. erratic phenomena 

[2] : The Collaborative International Dictionary of English v.0.48

erratic \errat"ic\, n.
   1. one who deviates from common and accepted opinions; one
      who is eccentric or preserve in his intellectual
      character.
      1913 webster

   2. a rogue. obs. --cockeram.
      1913 webster

   3. geol. any stone or material that has been borne away
      from its original site by natural agencies; esp., a large
      block or fragment of rock; a bowlder.
      1913 webster

   note: in the plural the term is applied especially to the
         loose gravel and stones on the earth's surface,
         including what is called drift.
         1913 webster

[3] : WordNet (r) 2.0

erratic
     adj 1: having no fixed course; "an erratic comet"; "his life
            followed a wandering course"; "a planetary vagabond"
            syn: planetary, wandering
     2: liable to sudden unpredictable change; "erratic behavior";
        "fickle weather"; "mercurial twists of temperament"; "a
        quicksilver character, cool and willful at one moment,
        utterly fragile the next" syn: fickle, mercurial, quicksilvera
     3: likely to perform unpredictably; "erratic winds are the bane
        of a sailor"; "a temperamental motor; sometimes it would
        start and sometimes it wouldn't"; "that beautiful but
        temperamental instrument the flute"- osbert lancaster
        syn: temperamental
see also:
planetary wandering fickle mercurial quicksilvera temperamental 

[4] : Moby Thesaurus II by Grady Ward, 1.0

271 moby thesaurus words for "erratic":
   aberrant, aberrative, abnormal, adrift, afloat, agnostic, aimless,
   alternating, ambiguous, amorphous, anomalistic, anomalous, bizarre,
   broken, capricious, careening, casual, catchy, chancy, changeable,
   changeful, changing, character, choppy, circuitous, crackpot,
   crank, crankish, cranky, crotchety, curving, departing, desultory,
   deviable, deviant, deviating, deviative, deviatory, devious, dicey,
   different, digressive, directionless, disarticulated, disconnected,
   discontinuous, discursive, disjunct, disordered, disorderly,
   dispersed, disproportionate, divagatory, divaricate, divergent,
   diversified, diversiform, dizzy, dotty, doubtful, doubting,
   dubious, eccentric, equivocal, erose, errant, exceptional,
   excursive, extraordinary, fast and loose, fey, fickle, fitful,
   flake, flaky, flickering, flighty, flitting, fluctuant,
   fluctuating, formless, freak, freakish, frivolous, funny, giddy,
   gratuitous, guttering, halting, haphazard, herky-jerky, hesitant,
   hesitating, heteroclite, heteromorphic, hit-or-miss, idiocratic,
   idiosyncratic, iffy, immethodical, impetuous, impulsive,
   incalculable, inchoate, incoherent, inconsistent, inconstant,
   indecisive, indemonstrable, indirect, indiscriminate, infirm,
   intermittent, intermitting, irregular, irresolute, irresponsible,
   jagged, jerky, kinky, kook, kooky, labyrinthine, lurching, maggoty,
   mazy, meandering, meaningless, mercurial, misshapen, moody, motley,
   mutable, nonconformist, nonstandard, nonsymmetrical, nonsystematic,
   nonuniform, nut, nutty, odd, oddball, orderless, out-of-the-way,
   outlandish, patchy, peculiar, planetary, planless, pluralistic,
   polysemous, promiscuous, quaint, queer, quirky, ragged, rambling,
   random, recluse, restless, rough, roundabout, roving,
   scatterbrained, scrappy, screwball, screwy, senseless, serpentine,
   shapeless, shifting, shifty, shuffling, singular, skeptical, snaky,
   snatchy, spasmatic, spasmic, spasmodic, spastic, spineless,
   sporadic, spotty, staggering, straggling, straggly, strange,
   strange duck, stray, straying, subnormal, swerving, systemless,
   touch-and-go, turning, twisted, twisting, unaccountable,
   unarranged, uncertain, unclassified, unconfirmable, uncontrolled,
   unconventional, unconvinced, undependable, undirected,
   undisciplined, undivinable, unequable, unequal, uneven, unfixed,
   unforeseeable, ungraded, unjoined, unmethodical, unmetrical,
   unnatural, unordered, unorganized, unorthodox, unpersuaded,
   unpredictable, unprovable, unregular, unreliable, unrestrained,
   unrhythmical, unsettled, unsorted, unstable, unstable as water,
   unstaid, unsteadfast, unsteady, unsure, unsymmetrical,
   unsystematic, ununiform, unusual, unverifiable, vacillating,
   vagarious, vagrant, vague, variable, variegated, variform, various,
   varying, veering, vicissitudinary, vicissitudinous, volatile,
   wacky, wandering, wanton, wavering, wavery, wavy, wayward, weird,
   weirdo, whimsical, winding, wishy-washy, wobbling, wobbly,
   zigzag

Erratic >> E Words
Erratic, definition of term: Erratic
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