From en.wikipedia.org:
GEACH is a surname. Notable people with the surname include:
- Carveth Geach (1928–2005), Chief Scout of the Boy Scouts of South Africa - David Geach (1923–2015), RAF bomb aimer - Peter Geach (1916–2013), British philosopher and professor - Portia Geach (1973–1959), Australian artist and feminist - Trevor Geach (1928–1996), South African cricketer [surname]