Ogee: a molding with an ogee-shaped profile, consisting (going from low to high) of a concave arc flowing into a convex arc, with vertical ends; an alternative name for such a molding is cyma reversa; talon is also used.
Oilcloth: heavy cotton or linen cloth with a linseed oil coating, semi-water-proof.
Oilstone: a type of fine grade blade shapening and honing stone One of the natural minerals commonly used in oilstones is Novaculite.
On Center: indicates the spacing of framing members; the measurement from the center of one member to the center of the nearest member.
Open Grained Wood: wood having large poers, for example ash, oak, chestnut or walnut.
Oriel: a projecting bay window carried on corbels, brackets or a cantilever.
Oriented Strand Board: a formed wood product panel, made by layering strands of wood in specific orientations. In appearance it may have a rough and variegated surface with the individual strips lying unevenly across each other.
Outrigger: the part of a rafter extending beyound the wall line.
Oven-dry Wood: wood dired in a ventilated oven until it is almost completely moisture free.