circularize
Concise Oxford English Dictionary © 2008 Oxford University Press:
circularize /ˈsəːkjʊlərʌɪz/ (or circularise)
▶verb
- 1 distribute a large number of letters or leaflets to.
- 2 make circular.
– derivatives
circularization noun.
circularization noun.
'circularize' also found in these Oxford entries:

