A honcho is the person who's in charge. The "head honcho" in your office probably bosses everyone else around.
Honcho is an informal word that was coined in the United States in the 1940s to mean "officer in charge," becoming especially popular with U.S. soldiers during the Korean War. Honcho comes from a Japanese word for "group leader," hancho, from han, "corps or squad," and cho, "head or chief." These days, the CEO of a company is as likely to be called a honcho as an Army general.