1.AdjectiveOf or pertaining to a circulation, especially to the circulatory system.
"circulatory diseases; circulatory organs"
2.AdjectiveCircular; going round.
"a circulatory letter"
3.NounA vessel with two portions unequally exposed to heat, and with connecting pipes or passages, through which the fluid rises from the overheated portion, and descends from the relatively colder, maintaining a circulation.