1. n. 
Small pieces of rock that break away due to the action of the bit teeth. Cuttings are screened out of the liquid mud system at the shale shakers and are monitored for composition, size, shape, color, texture, hydrocarbon content and other properties by the mud engineer, the mud logger and other on-site personnel. The mud logger usually captures samples of cuttings for subsequent analysis and archiving.
See: bridge, cable-tool drilling, circulate out, eccentricity, mechanical sticking, mud engineer, overbalance, pack off, pill, reciprocate, reverse circulation, rotary drilling, settling pit, shale shaker
2. n. 
Rock pieces dislodged by the drill bit as it cuts rock in the hole. Cuttings are distinct from cavings, rock debris that spalls as a result of wellbore instability. Visual inspection of rock at the shale shaker usually distinguishes cuttings from cavings.