(obsolete): A wrought-iron nail heaving a large flat head; -- used for fastening clouts to axletrees, plowshares, etc., also for studding timber, and for various purposes.
1866: They must have been light, for, reckoned by the hundred, the average is not very different from that of the hundred-weight of iron; and clout-nails must have been of moderate size, as the value varies very little from that of horseshoe-nails. — James Edwin Thorold Rogers, A History of Agriculture and Prices in England, Volume 1, p. 546.