(Zoöl.), a long, slender, spiral gastropod shell, especially of the genus Turritella and allied genera. See
Turritella. Screw steamer, a steamship propelled by a screw. Screw thread, the spiral rib
which forms a screw. Screw stone (Paleon.), the fossil stem of an encrinite. Screw tree (Bot.),
any plant of the genus Helicteres, consisting of about thirty species of tropical shrubs, with simple leaves
and spirally twisted, five-celled capsules; also called twisted-horn, and twisty. Screw valve, a
stop valve which is opened or closed by a screw. Screw worm (Zoöl.), the larva of an American
fly (Compsomyia macellaria), allied to the blowflies, which sometimes deposits its eggs in the nostrils,
or about wounds, in man and other animals, with fatal results. Screw wrench. (a) A wrench for
turning a screw. (b) A wrench with an adjustable jaw that is moved by a screw. To put the screw,
or screws, on, to use pressure upon, as for the purpose of extortion; to coerce. To put under the
screw or screws, to subject to pressure; to force. Wood screw, a metal screw with a sharp thread
of coarse pitch, adapted to holding fast in wood. See Illust. of Wood screw, under Wood.
(Screw) v. t. [imp. & p. p. Screwed ; p. pr. & vb. n. Screwing.]
1. To turn, as a screw; to apply a screw to; to press, fasten, or make firm, by means of a screw or screws; as,
to screw a lock on a door; to screw a press.
2. To force; to squeeze; to press, as by screws.
But screw your courage to the sticking place,Shak.
And we'll not fail.
3. Hence: To practice extortion upon; to oppress by unreasonable or extortionate exactions.
Our country landlords, by unmeasurable screwing and racking their tenants, have already reduced the
miserable people to a worse condition than the peasants in France.swift.
4. To twist; to distort; as, to screw his visage.
He screwed his face into a hardened smile.Dryden.
5. To examine rigidly, as a student; to subject to a severe examination. [Cant, American Colleges]
To screw out, to press out; to extort. - - To screw up, to force; to bring by violent pressure. Howell.
To screw in, to force in by turning or twisting.
(Screw), v. i.
1. To use violent mans in making exactions; to be oppressive or exacting. Howitt.
2. To turn one's self uneasily with a twisting motion; as, he screws about in his chair.