A proportion used in determining the dimensional relationship of a representation to that which it represents: a world map with a scale of 1:4,560,000. b. A calibrated line, as on a map or an architectural plan, indicating such a proportion.
Yttria (yttrium oxide, Y 2 O 3), was discovered by Johann Gadolin in 1794 in a mineral called gadolinite from Ytterby. Ytterby is the site of a quarry in Sweden which contains many unusual minerals containing erbium, terbium, and ytterbium as well as yttrium.
Define urticaria. urticaria synonyms, urticaria pronunciation, urticaria translation, English dictionary definition of urticaria. n. See hives. urâ²tiÂ·carâ²iÂ·al adj. n a skin condition characterized by the formation of itchy red or whitish raised patches, usually caused by an allergy....