Primitive axes of coördinate (Geom.), that system of axes to which the points of a magnitude are first referred, with reference to a second set or system, to which they are afterward referred. -- Primitive chord (Mus.), that chord, the lowest note of which is of the same literal denomination as the fundamental base of the harmony; -- opposed to derivative. Moore (Encyc. of Music). -- Primitive circle (Spherical Projection), the circle cut from the sphere to be projected, by the primitive plane. -- Primitive colors (Paint.), primary colors. See under Color. -- Primitive Fathers (Eccl.), the acknowledged Christian writers who flourished before the Council of Nice, A. D. 325. Shipley. -- Primitive groove (Anat.), a depression or groove in the epiblast of the primitive streak. It is not connected with the medullary groove, which appears later and in front of it. -- Primitive plane (Spherical Projection), the plane upon which the projections are made, generally coinciding with some principal circle of the sphere, as the equator or a meridian. -- Primitive rocks (Geol.), primary rocks. See under Primary. -- Primitive sheath. (Anat.) See Neurilemma. -- Primitive streak or trace (Anat.), an opaque and thickened band where the mesoblast first appears in the vertebrate blastoderm.

Syn. -- First; original; radical; pristine; ancient; primeval; antiquated; old-fashioned.