Definition of: underlay

(un′dər·lā′) v.t. ·laid, ·lay·ing
1. To place (one thing) under another.
2. To furnish with a base or lining.
3. Printing To support or raise by underlays.
—noun (un′dər·lā′)
1. Printing A piece of paper, etc., placed under certain parts of a printing form, to bring them to the proper level.
2. Mining An inclination, as of a lode.
3. A wager made at odds unfavorable to the better: opposed to overlay.