Webster's Revised Unabridged Dictionary · 1913

Underlay

Underlay , transitive verb

[Anglo-Saxon underlecgan. See Under, and Lay, transitive verb]

1.
To lay beneath; to put under.
2.
To raise or support by something laid under; as, to underlay a cut, plate, or the like, for printing. See Underlay, n., 2.
3.
To put a tap on (a shoe). [Provincial English]

Underlay , intransitive verb

(Mining) To incline from the vertical; to hade; -- said of a vein, fault, or lode.

Underlay , noun

1.
(Mining) The inclination of a vein, fault, or lode from the vertical; a hade; -- called also underlie.
2.
(Printing) A thickness of paper, pasteboard, or the like, placed under a cut, or stereotype plate, or under type, in the form, to bring it, or any part of it, to the proper height; also, something placed back of a part of the tympan, so as to secure the right impression.