Abraham-man was an old term for mendicant lunatics, or, more commonly, frauds who wandered England shamming madness so as to collect alms (1560s). According to the old explanation of the name (from at least 1640s), they originally were from Bethlehem Hospital, where in early times there was an Abraham ward or room for such persons, but the ward might have been named for the beggars.
Cabalistic word associated with the followers of Basilides the Gnostic, by 1680s, of uncertain origin and with many elaborate explanations. Also used in reference to a type of Gnostic amulet featuring a carved gem depicting a monstrous figure and obscure words or words connected to Hebrew or Egyptian religion (1725).
Abbreviate is the same word directly from Latin. The sound development that turned Latin -vi- to French -dg- is paralleled in assuage (from assuavidare) and deluge (from diluvium). Of writing, "shorten by omission," late 14c. Related: Abridged; abridging.