monarch monarch /ˈmɑːˌnɑːrk/

noun

1. () A nation's ruler or head of state usually by hereditary right  ( crowned head , monarch , sovereign )
   a nation's ruler or head of state usually by hereditary right
     The wise sovereign ruled over the kingdom with wisdom and compassion.
   The wise sovereign ruled over the kingdom with wisdom and compassion.
   
2. Large migratory American butterfly having deep orange wings with black and white markings; the larvae feed on milkweed  ( Danaus plexippus , milkweed butterfly , monarch , monarch butterfly )
   large migratory American butterfly having deep orange wings with black and white markings; the larvae feed on milkweed