early 15c., "in that area, around there; mid-15c., "near to that time, approximately thence," from Old English þær onbutan "about that place" + adverbial genitive -es; see there + about.
come at noon or thereabouts
he stayed in London or thereabouts for several weeks
ther-
therapeutic
therapist
therapy
there
thereabouts
thereafter
thereby
therefor
therefore
therefrom