Containing fossil ammonites.

A mechanism for preventing accidents in machinery. / (underwater diving) A diver's pause at a certain depth when ascending, to prevent decompression sickness.

(geology) A fossil fragment used to date a rock stratum.

(literature) Any of a group of mostly working-class and middle-class British playwrights and novelists who rose to prominence in the 1950s, their works being characterized by harshness, realism, an...