As a boy's name this is a pet form of Jeremy or Gerald, or occasionally of Gerard and Jerome. As a girl's name it is a variant spelling of Gerry, and is sometimes bestowed as an independent given name, as in the case of the American model and actress Jerry Hall (b. 1956).
English: habitational name from places in Buckinghamshire, Northamptonshire, and Staffordshire called Hartwell, from Old English heorot ‘stag’, ‘hart’ + wella ‘spring’, ‘stream’. In some cases the surname may have arisen from Hartwell in Hartfield, Sussex or Hartwell in Lamerton, Devon.