Col'li-mā'tion, n.

n. [Fr. collimation, from Lat. collimare, to aim, for which the lexicons and editions now write collineare, to direct something in a straight line, to aim, from con and lineare, from linea, line. See COLLINEATION.] The act of aiming at a mark; aim; the act of leveling, or of directing the sight to a fixed object.

Error of collimation, the deviation of the line of collimation of an astronomical or geodetical instrument from its normal or correct position with respect to the axis of motion of the instrument.—Line of collimation, the axial line of the telescope of an astronomical or geodetic instrument, or the line which passes through the optical center of the object-glass and the intersection of the cross-wires at its focus.