I. -ād.ə(r) noun
( -s )
: one that concentrates: as
a. : an apparatus by which something (as an ore or a solution) is concentrated ; sometimes : an industrial plant specializing in concentration (as of ore)
b. : a worker who tends concentrating apparatus
c. : a student who concentrates (in a particular field of study)
II. noun
1. : a mirror or group of mirrors that focus sunlight for use as an energy source
2. : a device in a computer network that collects data from separate low-volume transmission channels and retransmits it over a single high-volume channel