n. 1. A melting together; the act of melting; fusion. [ 1913 Webster ]

When sand and ashes are well melted together and suffered to cool, there is generated, by the colliquation, that sort of concretion we call “glass”. Boyle. [ 1913 Webster ]

2. (Med.) A processive wasting or melting away of the solid parts of the animal system with copious excretions of liquids by one or more passages. [ Obs. ] [ 1913 Webster ]

n. [ Cf. F. collimation, fr. a false reading (collimare) for L. collineare to direct in a straight line; col- + linea line. Cf. Collineation. ] The act of collimating; the adjustment of the line of the sights, as the axial line of the telescope of an instrument, into its proper position relative to the other parts of the instrument. [ 1913 Webster ]

Error of collimation, the deviation of the line collimation of an astronomical instrument from the position it ought to have 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. [ 1913 Webster ]