spīrˈal adjective

1. (in general but non-technical usage) winding like the thread of a screw
2. With parts arranged in spirals (botany)

1. A spiral line, course, or object
2. A two-dimensional curve, the locus of a point whose distance from a fixed point varies according to some rule as the radius vector revolves (mathematics)
3. (in general but non-technical usage) a helix
4. A gradual but continuous rise or fall, as of prices

1. To go in a spiral
2. (of stocks and shares) to decrease in value uncontrollably (informal)

To make spiral

spīralˈiform adjective

In or based on the shape of a spiral

spīrality /-alˈi-ti/ noun

spīrˈally adverb

spīrasˈter noun

(Gr astēr star) a coiled sponge spicule with radiating spines

spīrˈāted adjective

Spirally twisted

spīrˈēme noun

In mitosis, the coiled thread formed by nuclear chromatin

spīrˈic adjective

Like a tore or anchor-ring

A curve, the plane section of a tore

spīrillˈar adjective

spīrillōˈsis noun

Infection with a spirillum

spīrillˈum noun (pl spīrillˈa)

Any rigid, spiral-shaped bacterium of the genus Spirillum, eg S. minus that causes ratbite fever

spīˈroid adjective

With the form of, or like, a spiral

spīrˈy adjective

Spirally coiled

spiral arm noun

An arm of a spiral galaxy

spiral binding noun

A method of binding a book or notebook by threading a wire or plastic spiral through punched holes at the spine of each page

spiral bound adjective

spiral fracture noun (medicine)

A fracture of a bone caused by a sudden violent twisting movement

spiral galaxy noun (astronomy)

One of a large class of galaxies, with two spiral arms emerging from a bright central ellipsoidal nucleus about which they rotate

spiral ratchet screwdriver noun

A ratchet screwdriver which can be made to turn in either direction by downward pressure on a sleeve which applies torque to helical grooves in the shaft

spiral staircase noun

A staircase in the form of a spiral, with a central column around which the steps are built