'Crookes tube' definitions:

Definition of 'Crookes tube'

(from WordNet)
noun
The original gas-discharge cathode-ray tube

Definition of 'Crookes tube'

From: GCIDE
  • Crookes tube \Crookes" tube`\ (kr??ks" t?b`). (Phys.) A vacuum tube in which the exhaustion is carried to a very high degree, with the production of a distinct class of effects; -- so called from W. Crookes who introduced it. [1913 Webster]