Scrub n.
 1. One who labors hard and lives meanly; a mean fellow. “A sorry scrub.”
    We should go there in as proper a manner as possible; nor altogether like the scrubs about us.   --Goldsmith.
 2. Something small and mean.
 3. A worn-out brush.
 4. A thicket or jungle, often specified by the name of the prevailing plant; as, oak scrub, palmetto scrub, etc.
 5. Stock Breeding One of the common live stock of a region of no particular breed or not of pure breed, esp. when inferior in size, etc. [U.S.]
 6. Vegetation of inferior quality, though sometimes thick and impenetrable, growing in poor soil or in sand; also, brush; -- called also scrub brush. See Brush, above. [Australia & South Africa]
 7.  Forestry A low, straggling tree of inferior quality.
 Scrub bird Zool., an Australian passerine bird of the family Atrichornithidae, as Atrichia clamosa; -- called also brush bird.
 Scrub oak Bot., the popular name of several dwarfish species of oak. The scrub oak of New England and the Middle States is Quercus ilicifolia, a scraggy shrub; that of the Southern States is a small tree (Quercus Catesbaei); that of the Rocky Mountain region is Quercus undulata, var. Gambelii.
 Scrub robin Zool., an Australian singing bird of the genus Drymodes.