Circulation
late Middle English (denoting continuous distillation of a liquid): from Latin circulatio(n- ), from the verb circulare (see circulate).
wiktionary
From Middle English circulacioun, from Latin circulatio. Morphologically circulate + -ion
etymonline
circulation (n.)
mid-15c., circulacioun, in alchemy, "process of changing something from one element into another," from Latin circulationem (nominative circulatio), noun of action from past-participle stem of circulare "to form a circle," from circulus "small ring" (see circle (n.)).
Of blood, "act of moving so that it returns and begins again," first by William Harvey, 1620s. Meaning "act or state of being distributed" is from 1680s; that of "extent to which a thing circulates" (of periodical publications) is from 1847.
