Slaughter (Upper and Lower), (m. p. &v.) 21/2m. S.W. of Stow-on-the-Wold. D. Sclostre. Anc. Ch. No. 45. (1183.) Sloctre. P.R. 1175-6 Scloctre and Schloclitres. P.C. 1221. Slohtres.-Sloughter'.-R.H. Sloustre. C.R.G1. 1298 Slouhtre. A.S. Slohtre(o) or Slach-treo(o), from A. S. Slah f. Sloe, and treo : tree. The modern spelling is due to the tendency to popular etymology. The Blackthorn-tree, or sloe. - Gloucestershire - Place Names, Baddeley
"Slaughter, Lower, anciently Sclostre,
Is a small parish, six miles N. from Northleach, twenty three N. E. from Gloucester, and containing 1000 acres: the soil is in general nearly the same as the last, as well as are the agricultural purposes to which it is applied.
Sclostre is said to be derived from Scio, the name of some Saxon proprietor, and tre a place, signifying Sclo's place or possession." - History of the County of Gloucestershire 1803