I. ˈ ̷ ̷| ̷ ̷ adjective
Etymology: probably from cock (I) + sure
1. obsolete
a. : quite safe
b. : of certain outcome
c. : sure of doing, receiving, or acting as indicated
2.
a. : marked by certainty and conviction with no doubt or reservation : perfectly sure
not being cocksure of my position, [I] have often lacked the passionate conviction — W.A.White
b. : given to or marked by overconfidence, presumptuousness, lack of thoroughness, or cockiness
how cautious and profound a thinker he was — how very far from being that arrogant and cocksure materialist — Aldous Huxley
Synonyms: see sure
II. adverb
: with complete security or certainty