early 13c., "white, pale, colorless," from Old French blanc "white, shining," from Frankish *blank "white, gleaming," or some other Germanic source (compare Old Norse blakkr, Old English blanca "white horse;" Old High German blanc, blanch; German blank "shining, bright"), from Proto-Germanic *blangkaz "to shine, dazzle," extended form of PIE root *bhel- (1) "to shine, flash, burn," also "shining white."
Meaning "having empty spaces" evolved c. 1400. Sense of "void of expression" (a blank look) is from 1550s. Spanish blanco, Italian bianco are said to be from Germanic. Related: Blankly, blankness.
Old English fearn "fern," from Proto-Germanic *farno- (source also of Old Saxon farn, Middle Dutch vaern, Dutch varen, Old High German farn, German Farn). Watkins and other sources propose an etymology on the notion of "having feathery fronds" from a possible PIE *por-no- "feather, wing" (source also of Sanskrit parnam "feather, leaf;" Lithuanian papartis "fern;" Russian paporot'; Greek pteris "fern"), a proposed suffixed form of the root *per- (2) "to lead, pass over," on the notion of "that which carries a bird in flight."
The plant's ability to appear as if from nothing accounts for the ancient belief that fern seeds conferred invisibility (1590s). Filicology "science or study of ferns" (1848) is from Latin filix "fern."
Old English blæcan, of cloth or fabric, "to make white by removing color, whiten" (by exposure to chemical agents or the sun), from Proto-Germanic *blaikjan "to make white" (source also of Old Saxon blek, Old Norse bleikr, Dutch bleek, Old High German bleih, German bleich "pale;" Old Norse bleikja, Dutch bleken, German bleichen "to make white, cause to fade"), from PIE root *bhel- (1) "to shine, flash, burn," also "shining white."
The same root probably produced black, perhaps because both black and white are colorless, or because both are associated in different ways with burning. Compare Old English scimian meaning both "to shine" and "to dim, grow dusky, grow dark," which is related to the source of shine. Intransitive sense "become white" is from 1610s. Related: Bleached; bleaching. The past participle in Middle English was sometimes blaught.
"person who seeks or is put forward for an office by election or appointment," c. 1600, from Latin candidatus "one aspiring to office," originally "white-robed," past participle of candidare "to make white or bright," from candidus past participle of candere "to shine," from PIE root *kand- "to shine." White was the usual color of the Roman toga, but office-seekers in ancient Rome wore a gleaming white toga (togacandida), probably whitened with fine powdered chalk, presumably to indicate the purity of their intentions in seeking a role in civic affairs.