curbstone
Multiple Entries:curbstone kerbstone
Concise Oxford English Dictionary © 2008 Oxford University Press:
curbstone/ˈkɜːbstəʊn/
▶noun US spelling of kerbstone.
Concise Oxford English Dictionary © 2008 Oxford University Press:
kerbstone /ˈkɜːbstəʊn/ (US curbstone)
▶noun a long, narrow stone or concrete block, laid end to end with others to form a kerb.
'curbstone' also found in these Oxford entries:

