1 Feeling or showing confidence in oneself or one’s abilities or qualities.
2 Feeling or showing certainty about something.
Late 16th century: from French confident(e), from Italian confidente, from Latin confident- ‘having full trust’, from the verb confidere, from con- (expressing intensive force) + fidere ‘trust’.
Harry was confident his design would work just as well as available commercial machines. He was also very proud it could be made cheaply, on-site, from local materials.