n.1 a sovereign with the title of king, queen, emperor, empress, or the equivalent.
2 a supreme ruler.
3 a powerful or pre-eminent person.
4 a large orange and black butterfly, Danaus plexippus.
Derivatives:
monarchal adj. monarchic adj. monarchical adj. monarchically adv.
Etymology: ME f. F monarque or LL monarcha f. Gk monarkhes, -os, f. monos alone + arkho to rule