Synonyms for Sand (same or very similar meaning)
WordNet sense 1 (French writer known for works concerning women's rights and independence (1804-1876)):
Amandine Aurore Lucie Dupin, Baroness Dudevant, George SandWordNet sense 2 (fortitude and determination):
backbone, grit, gumption, guts, moxieWordNet sense 3 (rub with sandpaper):
sandpaperFrom the ODE community, based on WordNetadd/edit