- adjective referring to the movement of an object around something
- A region of space surrounding one or more atomic nuclei, in which the probability of an electron being located is greatest. The charge of such an electron is distributed in this space. No more than two electrons may occupy the same orbital. Also called atomic orbital.
- Pertaining to an orbit.
- noun an acid house party. In 1989 there was a vogue for large-scale gatherings of adolescent party goers, usually paying to attend clandestine dance celebrations which often ended in confrontations with the police. The practice was part of the acid house cult in which the drug ecstasy played an integral part. The parties in question revived the dated term rave and were held within reach of the London orbital motorway, the M25, hence the names.