Definition of picas:
(n) :
(pathology, usually uncountable) A disorder characterized by appetite and craving for non-edible substances, such as chalk, clay, dirt, ice, or sand.
(n) :
(typography, printing, uncountable) A size of type between small pica and English, now standardized as 12-point.
(n) :
(typography, countable) A unit of length equivalent to 12 points, officially ³⁵⁄₈₃ cm (0.166 in) after 1886 but now (computing) ¹⁄₆ in.
(n) :
(countable) A magpie.
(n) :
(typography, uncountable, usually with qualifier) A font of this size.
(n) :
(uncommon, ecclesiastical) A pie or directory: the book directing Roman Catholic observance of saints' days and other feasts under various calendars.