An intervertebral disc.
A vinyl phonograph / gramophone record.
The flat surface of an organ, as a leaf, any flat, round growth.
Venus's disc cut off light from the Sun.
Something resembling a disc.
A thin, flat, circular plate or similar object.
To move towards, or operate at, zero blade pitch, orienting the propeller blades face-on to the oncoming airflow and maximising the drag generated by the propeller.
To harrow with a disc harrow.
encirclement
enclosing, skirting