costermonger A street-vendor, a hawker of fresh fruits, vegetables, fish, etc.; also simply coster. This British expression comes from the earlier costardmonger ‘apple-seller’ (costard ‘a large, ribbed variety of apple’ + monger ‘dealer, trader’). It has been in use since 1514.

flatfoot A police officer. This expression, in widespread use since the early 20th century, implies that a police officer on a beat becomes flatfooted from walking. Flatfoot and other expressions of derision became firmly entrenched in American speech during the Prohibition era (1920-33) when the general public was particularly contemptuous of those who enforced the law.

flesh-tailor A surgeon. The derivation of this British colloquialism is obvious.

free-lance An unaffiliated person who acts on his own judgment; a writer or journalist who submits work to various publishers without actually being employed by any of them; a person hired on a part-time or temporary basis to perform tasks for which he has been specially trained. This expression dates from the Middle Ages when, after the Crusades, bands of knights offered their services to any country that was willing to pay. Also known as mercenaries or free companies, these bands were commonly called free-lances in reference to their knightly weapon, the lance. Eventually the term was applied to unaffiliated politicians. In contemporary usage, however, a free-lancer is anyone (though usually a writer) who offers his services on a temporary basis with payment upon completion of the work, as opposed to payment in the form of a salary or retainer.

gandy dancer Railroad slang for a section hand or tracklayer. The term, in use as early as 1923, derives from the rhythmic motions of railroad workers who laid tracks with tools made by the now defunct Gandy Manufacturing Company of Chicago.

ghost writer A person who is paid to write a speech, article, or book—particularly an autobiography—for another, usually more famous person who receives and accepts credit for its authorship; a hack writer. This expression alludes to the classic definition of ghost ‘an unseen spirit or being existing among living persons.’ The implication is that though a ghost writer exists, his presence is hidden from the general public; thus, his existence is unknown or unrecognized. A back formation is to ghostwrite or to ghost ‘to write for another who accepts credit for the work.’

gumshoe A detective, plainclothesman, or police officer; so called from the rubber-soled shoes reputedly worn by those gentlemen in order to assure noiseless movement. Consequently gumshoe can also be used as a verb meaning ‘to move silently; to sneak, skulk, or pussyfoot.’

ink-slinger A disparaging appellation for a writer, especially one who writes for his livelihood; also ink-jerker, -spiller, or -shedder. The reference is probably to a newspaper writer under such pressure to finish an article by a specified deadline that he “slings” the ink onto the paper without regard for the quality of writing. This American slang term dates from the latter half of the 19th century. The noun ink-slinging appeared in The Spectator (November, 1896):

pencil pusher An office worker who does a considerable amount of writing. This U.S. slang term is a disparaging comment on the lack of productive labor in office work. The phrase also implies that such work is menial and mechanical.

sawbones A surgeon; any doctor. The allusion in this term is gruesomely obvious.

shrink A psychiatrist or psychoanalyst. This derogatory expression is a shortening of headshrinker, which may have been coined by analogy to the primitive tribal custom, practised by medicine men, of shrinking a decapitated head by removing the skull and stuffing the skin with hot sand.