De`vi*a"tion (?), n. [LL. deviatio: cf. F. d'eviation.]
The act of deviating; a wandering from the way; variation from the common way, from an established rule, etc.; departure, as from the right course or the path of duty.
The state or result of having deviated; a transgression; an act of sin; an error; an offense.
The voluntary and unnecessary departure of a ship from, or delay in, the regular and usual course of the specific voyage insured, thus releasing the underwriters from their responsibility.
Deviation of a falling body Physics, that deviation from a strictly vertical line of descent which occurs in a body falling freely, in consequence of the rotation of the earth. -- Deviation of the compass, the angle which the needle of a ship's compass makes with the magnetic meridian by reason of the magnetism of the iron parts of the ship. -- Deviation of the line of the vertical, the difference between the actual direction of a plumb line and the direction it would have if the earth were a perfect ellipsoid and homogeneous, -- caused by the attraction of a mountain, or irregularities in the earth's density.
© Webster 1913.