sink

Here the object is the hole itself, not something pushed into it. You sink a well, a borehole or a shaft, and the verb implies working straight downward rather than across. The same idea becomes a thing in the small mining excavation, which is a sink in the noun sense.

Here the descent is a loss of strength rather than of height, and it reaches well beyond the sickbed. Shakespeare's Macbeth has a whole country that "sinks beneath the yoke," and John Mortimer's The Whole Art of Husbandry (1721) warns against letting a fire "sink or slacken" under drying hops. The verb is intransitive: things sink this way on their own, and the causative job of dragging something down belongs to the "degrade" meaning.

Moral descent usually comes with a measure of how far. The fixed frame is sink so low as to plus a verb: “Who would sink so low as to steal change from veterans?” Alternatively, sink to plus a noun names the depth reached: sink to cheating, sink to such cruelty. Either way the tone is one of indignation, and the question form is common.

Geologists use sink as shorthand for sinkhole. It is a closed hollow that opens where soluble bedrock such as limestone or gypsum dissolves and the ground above slumps or collapses into the void. Sinks are a hallmark of karst landscapes. The water-collecting hollow is defined by having no outlet, while this one is defined by how it formed.

Drinking slang counts its drinks: you sink pints, ciders, a glass of wine. The progressive is natural. Barbara Copperthwaite's The Girl in the Missing Poster (2021) mentions “all the Diamond White ciders she'd been sinking.” The verb belongs to casual talk among friends. It would sound out of place on a menu or in a doctor's question about how much someone drinks.

In a flow network, one vertex is designated as the endpoint that absorbs everything routed through the network, paired with a starting vertex that supplies the flow. Max-flow problems ask how much can be delivered to this point. Keep it apart from the structural graph sense, which names any node with no outgoing edges. Here the vertex is fixed by the problem's setup rather than read off its edges.

The notion is purely structural: a vertex with out-degree zero. Every edge touching it points inward, so a walk that reaches it can go no further. In a topological sort it comes after every vertex whose edges lead into it. Nothing about flow or purpose is implied, only the direction of the arrows.

Ecologists use the word as half of a pair, in source–sink dynamics. A productive source habitat exports its surplus individuals, and a sink takes them in. The sink's own growth rate is negative, so without steady immigration its population would dwindle to local extinction. Calling a habitat a sink says nothing about how it looks. The term describes its demographic balance.

Event-driven code borrows the flow picture. A producer emits notifications, and the sink is where they arrive, whether that is a handler, a callback or a logger registered for the purpose. The design keeps the two apart, so the code raising events need not know who consumes them. Programmers often name a sink by its job, as in a logging sink.

As an uncountable noun of motion, the word appears most often in the compound sink rate, the speed at which something descends. In aviation the stakes are concrete: an excessive sink rate at touchdown can collapse an aircraft's landing gear. Outside such compounds, descent or fall is usually the more natural word.

Baseball talk measures this like a quantity, never as “a sink”: a two-seamer has heavy sink, and a good one has late sink. The downward break comes from the seam orientation and the spin given at release. It drops the ball beneath the bat's path, so batters tend to hit it into the ground. The pitch itself is the sinker, and sink is what it does.

Game designers pair the word with faucet. Faucets pour currency into a game's economy, and sinks drain it back out, so prices stay stable as players accumulate wealth. The usual form names the currency, as in a gold sink, and a well-run economy balances one against the other.

The drain becomes a moral image here: a place into which vice and misery run and collect. The set phrase is a sink of iniquity, and the noun usually takes an of-phrase naming what has gathered there. It is a word of condemnation rather than description, so it judges a place as much as it names one.

Stage machinery gives the word a theatrical meaning. The sink lowers an entire flat smoothly into the cellar beneath the boards, worked with counterweights and bridge mechanisms so that scenery can vanish quickly. The effect relies on the audience seeing a wall descend rather than being carried off. It is part of the same downward vocabulary as the trap.

Miners use the word for a modest dig. A sink goes only deep enough to prove a seam or reach ore near the surface, without becoming a full shaft. The difference is depth and purpose: a sink explores, while a shaft serves a working mine.

Death is reported here as a gradual going-down, often in the progressive. Sinking fast describes someone near the end, as with Gömbös in C. A. Macartney's October Fifteenth (1956). C. C. Richards's 1865 report on a case of fatty tumours says the patient “never rallied, but sank.” Rally is the natural opposite. Since the use is archaic, write die when the meaning must be unmistakable.

An old slang use pictures putting something under, out of view. Frederick William Robertson's 1849 sermon describes a courtly willingness to “sink obnoxious truths.” The objects are things one would rather not have surface, such as truths, a report or one's pride. Because the use is both archaic and slang, it now reads as deliberately old-fashioned. Suppress or set aside says the same thing plainly.