operable wall
operable partition
A partition composed of a number of large panels which are hung from a ceiling track, permitting the panels to be moved easily from their closed position (in which the panels form a partition) to an open position (in which the panels are stacked against each other); the panels also may be supported by a floor track.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.