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.
Croon (kr&oomac;n), v. i. [OE. croinen, cf. D. kreunen to moan. √24.] 1. To make a continuous hollow moan, as cattle do when in pain. [Scot.] Jamieson.