- Spanish soldier: hero of the wars against the Moors.
- Le Cid.
- the displacement of an engine measured in cubic inches: My old car had a 302 c.i.d. engine.
- Criminal Investigation Department of Scotland Yard.
- El or the. original name Rodrigo Diaz de Vivar. ?1043–99, Spanish soldier and hero of the wars against the Moors
- (in Britain) Criminal Investigation Department; the detective division of a police force
- cruel, inhumane, and degrading: denoting the brutal and demeaning treatment of prisoners