| Term | Definition |
| Occluded branch stub | Pruned branch stub or dead branch, where the cut end has become enclosed by wood fibres inside the piece of timber. |
| Overgrowth of injury | Irregular growth and callus tissue that has grown over an injury in the tree’s stem. Generally also contains resin or gum between the injured wood and new wood tissue. |
| Pitch | Accumulation of resin in a softwood board. |
| Pith | Soft core in the centre of a tree trunk. |
| Planer gauged (PG) | Framing timber that has been sized (or ‘skip dressed’ in a planer) – sometimes called ‘rougher headed’ when it has small grooves along the length of the piece. |
| Quartersawn | Timber that is sawn so that the growth rings are inclined at more than 45 degrees to the wide face. |