Sy*zyg"i*al (?), a. Pertaining to a syzygy.
Syz"y*gy (sz"*j), n.; pl. Syzygies (- jz). [L. syzygia a joining
together, conjunction, Gr. syzygi`a; sy`n with + zeygny`nai to join,
zygo`n yoke: cf. F. syzygie. See Yoke, n.] 1. (Astron.) The point of an
orbit, as of the moon or a planet, at which it is in conjunction or
opposition; -- commonly used in the plural.
2. (Gr. & L. Pros.) The coupling together of different feet; as, in
Greek verse, an iambic syzygy.
3. (Zoöl.) (a) Any one of the segments of an arm of a crinoid composed
of two joints so closely united that the line of union is obliterated
on the outer, though visible on the inner, side. (b) The immovable
union of two joints of a crinoidal arm.
Line of syzygies (Astron.), the straight line connecting the earth, the
sun, and the moon or a planet, when the latter is in conjunction or
opposition; -- used chiefly of the moon.