From: Reaney, P H, (ed. Wilson, R M), 1997, Oxford Dictionary of English Surnames, 3rd ed., OUP, Oxford, unless otherwise stated.
Earliest in Andrew’s Kindred: John Gamble, born about 1795, Nailstone, Leicestershire.
From Old Norse Gamall, old.
Earliest in Andrew’s Kindred: Samuel Gazy, born about 1768, Rowington, Warwickshire.
I cannot make any progress on this. It seems specific to Leicestershire and Warwickshire.
Earliest in Andrew’s Kindred: Ann Goacher, born about 1798, Measham, Derbyshire.
From Middle English chere, Old French ciere, face: a person of cheery appearance. Wilhelmus dictus Godechere 1343, G F Black, Surnames of Scotland, New York, 1943.
Earliest in Andrew’s Kindred: Thomas Gozzard, born about 1834, Fazeley, Staffordshire.
From Old English gos and hierde, goose-herd.
Earliest in Andrew’s Kindred: George Gratrix, born 1716, Longdon-by-Lichfield, Staffordshire.
William Gretorex, 1743, Bisham Parish Registers, Berkshire. From Gretorakes, Derbyshire. Reaney does not put forward meaning. A range of online sources indicate great ridge and dweller by the ridge or hill.
Earliest in Andrew’s Kindred: John Gregory, born about 1820, Sheffield, Yorkshire.
From a personal name. From Ancient Greek Gregorios, “to be watchful”. Also Roman Gregorius, from grex, gregis, flock and herd, influenced by Christian image of the good shepherd. Evidently, sixteen popes found it apposite.
Earliest in Andrew’s Kindred: Richard Gretton, born about 1832, Swadlincote, Derbyshire.
From the place Gretton, Gloucestershire or Northamptonshire.