"to sail round, pass round by water," 1630s, from Latin circumnavigatus, past participle of circumnavigare "to sail round," from circum "around" (see circum-) + navigare (see navigation). Related: Circumnavigated; circumnavigating; circumnavigable.
word-forming element attached to verbs, making nouns of state, condition, or action, from French -ion or directly from Latin -ionem (nominative -io, genitive -ionis), common suffix forming abstract nouns from verbs.
<a href="https://www.etymonline.com/word/circumnavigation">Etymology of circumnavigation by etymonline</a>
Harper, D. (n.d.). Etymology of circumnavigation. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/circumnavigation