Any engaged column or colonnette that is supported by a corbel or bracket and appears to support a vault rib or clustered ribs above it.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
A colonette supported on a corbel or bracket which appears to support a rib of vaulting.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.