Mid 16th century; earliest use found in Hall's Vnion: Edward IV. Apparently originally a misprint for bycoket, incorporating a preceding indefinite article, unless reflecting an actual spoken variant with attraction of the indefinite article; subsequently shortened by Holinshed, and altered again in a later edition of Holinshed's text, perhaps as a result of misreading of the form abacoc forms (although this is apparently first attested later). Subsequently popularized by dictionaries ultimately informed by editions of Holinshed.