See Also: spiral CT(medicine)
spiral(2)(dictionary)
spiral(3)(dictionary)
spiral(4)(dictionary)
Spiral(medicine)
spiral(1)(dictionary)
spiral membrane(medicine)
spiral organ(medicine)
spiral plate(medicine)
spiral line(medicine)

spiral(1) (iou)



spiral adjective1 & adverb. M16.
[French, or medieval Latin spiralis, from Latin spira SPIRE noun3: see -AL1.]
A. adjective.
Winding continuously round a fixed point at a steadily increasing or decreasing distance in the same plane. M16.
Forming a continuous curve which winds like the thread of a screw in a cylindrical or conical manner; helical. M16.
A. Burgess Spiral stone steps worn by a century..of monkish feet.
b. Medicine. Of a fracture: curving round a long bone lengthwise. L19.
= spiral-bound below. L20.
Special collocations: spiral arm an arm of a spiral galaxy. spiral balance a device for measuring weight by the torsion of a spiral spring. spiral bevel gear a bevel gear that is also a spiral gear. spiral binding: in which a helical wire passes through a closely spaced row of holes near the inside edge of each leaf. spiral-bound adjective (of a notebook etc.) having spiral binding. spiral cleavage Zoology a pattern of embryogenesis characteristic of certain phyla of protostomes, in which the third cell division is asymmetrical and destroys all but four-fold rotational symmetry. spiral divergence Aeronautics = spiral instability below. spiral galaxy a galaxy in which stars and gas clouds are concentrated along arcs or arms that appear to spiral from a central nucleus. spiral gear a gear wheel with teeth cut obliquely to the axis and curved to form part of a spiral; esp. a skew gear of this kind. spiral instability Aeronautics: in which an aeroplane undergoing a banked turn tends to enter a descending spiral as a result of side-slipping and reduction of the radius of turn. spiral nebula (now chiefly Hist.) a spiral galaxy. spiral stability Aeronautics the capacity of an aeroplane not to enter a spiral while executing a banked turn, or to recover from a steeply-banked spiral path. spiral staircase a staircase rising in a spiral round a central axis. spiral thickening Botany (in the tracheary elements of the xylem, esp. the protoxylem) a thickening of the cell wall in which the secondary wall is laid down in the form of a continuous helix.
b. adverb. Spirally. rare. E18.
spi'rality noun spiral character; the degree of a spiral curve: M19.
spirally adverb so as to form a spiral; in a spiral course: E17.