'Holarctic' definitions:

Definition of 'Holarctic'

From: GCIDE

Holarctic \Hol"arc*tic\, a. [Holo- + arctic.] Of or pert. to the arctic regions collectively; specif. (Zo["o]geography), designating a realm or region including the northern parts of the Old and the New World. It comprises the Palearctic and Nearctic regions or subregions. [Webster 1913 Suppl.]