mob: [17] Mob is famous as one of the then new ‘slang’ abbreviations against which Joseph Addison and Jonathan Swift inveighed at the beginning of the 18th century (others included pozz for positively and rep for reputation). Mob was short for mobile, which itself was a truncated form of mobile vulgus, a Latin phrase meaning ‘fickle crowd’. Latin mōbilis ‘movable’, hence metaphorically ‘fickle’ (source of English mobile [15]), came from the base of the verb movēre ‘move’ (source of English move). => mobile, move
