back hearth[′bak ‚härth]
That part of the hearth (or floor) which is contained within the fireplace itself. Also known as inner hearth.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The fireproof floor under the grate area upon which a fire is built.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
back hearth, inner hearth
That part of the hearth, or floor, which is contained within the jambs of the fireplace.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.