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. [Geometry|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.

© [Webster 1913].

Contact (definition)