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1. A piece of timber inserted in a roof, floor, wooden partition, or the like, to support a header which in turn supports the ends of the joists, rafters, studs, etc.
2. A small horizontal beam, as in a floor, into which the ends of one or more joists are framed; often named from the place of use as a hearth trimmer, stair trimmer, etc.
3. A trimmer arch.
4. Variously shaped ceramic tile used as bases, caps, corners, moldings, and angles, as necessary to complete an installation and to satisfy sanitary and architectural requirements.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.