Roger North, after Sir Peter Lely (1680) – image: National Portrait Gallery
a riotous or disorderly crowd of people
In the late 16th century, English borrowed from classical Latin the expression mobile vulgus, meaning the fickle crowd, the changeable common people. Around 1599, the English Roman Catholic priest and conspirator William Watson (circa 1559-1603) wrote of
the ignorance, lightnes & ever blindly weyghed affecccion of yᵉ [= the] mobile vulgus.
This expression was used as late as 1925 by the American author, editor and journalist Henry Louis Mencken (1880-1956):
Even when mobile vulgus is not enraged against the criminal, and hence eager to see him barbarously used, it is delighted by the [judicial] battle that goes on over him.
The expression was shortened to mobile in the second half of the 17th century. For example, the English poet and playwright Thomas Shadwell (circa 1640-92) wrote the following in The libertine: a tragedy (1676):
D’ hear that noise? the remaining Rogues have rais’d the Mobile, and are coming upon us.
The same author was the first known user of mob, shortening of mobile, in his comedy The squire of Alsatia (1688):
“Here honest Mob, course this Whore to some purpose. A Whore, a Whore, a Whore.”
She runs out, the Rabble run after, and tear her, crying, a Whore, a Whore.
The Spectator of 4th August 1711 attributed this and other shortenings to the English people’s “natural aversion to loquacity”:
It is perhaps this humour of speaking no more than we needs must, which has so miserably curtailed some of our words, that in familiar writings and conversations they often lose all but their ﬁrst syllables, as in ‘mob. rep. pos. incog.’ and the like.
In Examen: or, An Enquiry into the Credit and Veracity of a Pretended Complete History, published in 1740, the English lawyer and biographer Roger North (1651-1734), describing the Pope-burning procession of 17th November 1680, wrote, about the King’s Head Club in London:
I may note that the Rabble first changed their title, and were called ‘the Mob’ in the assemblies of this Club. It was their Beast of Burthen, and called first, ‘mobile vulgus’, but fell naturally into the contraction of one syllable, and ever since is become proper English.
And, in the Introduction to A Complete Collection Of Genteel and Ingenious Conversation, According to the Most Polite Mode and Method Now Used At Court, and in the Best Companies of England (published in 1738), the Irish satirist, poet and Anglican cleric Jonathan Swift (1667-1745) made the purported author of the book, Simon Wagstaff, explain that the reader will meet with
some Abbreviations exquisitely refined ; as, Pozz for Positive ; Mobb for Mobile ; Phizz for Physiognomy ; Rep for Reputation ; Plenipo for Plenipotentiary ; Incog for. Incognito ; Hypps, or Hippo, for Hypocondriacks ; Bam for Bamboozle ; and Bamboozle for God knows what ; whereby much Time is saved, and the high Road to Conversation cut short by many a Mile.