Defensive outer wall of stone or earth. Rampart walk: path along the inner face.
Ramped
Of a stair-rail, dado etc: with a steep concave curve just short of the newel, or in line with it.
Random rubble
Masonry whose stones are wholly or partly in a rough state and laid in a random pattern. Coursed: coursed stones with rough faces. Random: uncoursed stones. Snecked: with courses broken by smaller stones (snecks).
Ratcourse
(Scots): Projecting string-course on a doocot (dovecote) to deter rats.
Rath
(Irish): Circular or near-circular enclosure consisting of one or more earthen (or occasionally stone) banks, classified according to the number of surrounding ditches as univallate, bivallate or trivallate. Most date from early Christian times and housed single farms or served as cattle enclosures for farms. Also called ring forts.
Rebate
Rectangular section cut out of a masonry edge to receive a shutter, door, window, etc.
Rebus
A heraldic pun, e.g. a fiery cock for Cockburn.
Reeding
Series of convex mouldings, the reverse of fluting.
Refectory
Dining hall of a monastery, college or similar establishment.