Contact \Con"tact\, n. [L. contactus, fr. contingere, -tactum, to touch on all sides. See Contingent.]

1. A close union or junction of bodies; a touching or meeting.

2. (Geom.) The property of two curves, or surfaces, which meet, and at the point of meeting have a common direction.

3. (Mining) The plane between two adjacent bodies of dissimilar rock. --Raymond.

Contact level, a delicate level so pivoted as to tilt when two parts of a measuring apparatus come into contact with each other; -- used in precise determinations of lengths and in the accurate graduation of instruments.

Source: Webster's Revised Unabridged Dictionary (1913)