1.  dandruff(n = noun.state) - a condition in which white scales of dead skin are shed by the scalp;
is a kind of pityriasis

2.  dandruff(n = noun.object) - loose scales shed from the scalp; "I could see the dandruff on her shoulders"
is a kind of exfoliation, scale, scurf

dandruff, n.
1 dead skin in small scales among the hair.
2 the condition of having this.

Etymology:
16th c.: -ruff perh. rel. to ME rove scurfiness f. ON hrufa or MLG, MDu. rove

N  uncleanness, impurity, immundity, immundicity, impurity, defilement, contamination, defoedation, soilure, soiliness, abomination, leaven, taint, tainture, fetor, decay, putrescence, putrefaction, corruption, mold, must, mildew, dry rot, mucor, rubigo, slovenry, slovenliness, squalor, dowdy, drab, slut, malkin, slattern, sloven, slammerkin, slammock, slummock, scrub, draggle-tail, mudlark, dust-man, sweep, beast, dirt, filth, soil, slop, dust, cobweb, flue, smoke, soot, smudge, smut, grit, grime, raff, sossle, sozzle, sordes, dregs, grounds, lees, argol, sediment, settlement heeltap, dross, drossiness, mother, precipitate, scoriae, ashes, cinders, recrement, slag, scum, froth, hogwash, ditchwater, dishwater, bilgewater, rinsings, cheeseparings, sweepings, offscourings, outscourings, off scum, caput mortuum, residuum, sprue, fecula, clinker, draff, scurf, scurfiness, exuviae, morphea, fur, furfur, dandruff, tartar, riffraff, vermin, louse, flea, bug, chinch, mud, mire, quagmire, alluvium, silt, sludge, slime, slush, slosh, sposh, spawn, offal, gurry, lientery, garbage, carrion, excreta, slough, peccant humor, pus, matter, suppuration, lienteria, faeces, feces, excrement, ordure, dung, crap, shit, sewage, sewerage, muck, coprolite, guano, manure, compost, dunghill, colluvies, mixen, midden, bog, laystall, sink, privy, jakes, toilet, john, head, cess, cesspool, sump, sough, cloaca, latrines, drain, sewer, common sewer, Cloacina, dust hole, sty, pigsty, lair, den, Augean stable, sink of corruption, slum, rookery, dirty, filthy, grimy, unclean, impure, soiled, not to be handled with kid gloves, dusty, snuffy, smutty, sooty, smoky, thick, turbid, dreggy, slimy, mussy, slovenly, untidy, messy, uncleanly, unkempt, sluttish, dowdy, draggle-tailed, uncombed, unscoured, unswept, unwiped, unwashed, unstrained, unpurified, squalid, lutose, slammocky, slummocky, sozzly, nasty, coarse, foul, offensive, abominable, beastly, reeky, reechy, fetid, decayed, moldy, musty, mildewed, rusty, moth-eaten, mucid, rancid, weak, bad, gone bad, etercoral, lentiginous, touched, fusty, effete, reasty, rotten, corrupt, tainted, high, flyblown, maggoty, putrid, putrefactive, putrescent, putrefied, saprogenic, saprogenous, purulent, carious, peccant, fecal, feculent, stercoraceous, excrementitious, scurfy, scurvy, impetiginous, gory, bloody, rotting, rotten as a pear, rotten as cheese, crapulous, gross, fimetarious, fimicolous, they that touch pitch will be defiled.