The simian crease is one of the listed signs in Down Syndrome which would imply there's some genetic factor at play. My eldest daughter has a simian crease on one hand and the other hand is 'normal'.
Sovereign definition, a monarch; a king, queen, or other supreme ruler. See more.
Princeton's WordNet(5.00 / 2 votes)Rate this definition: 1  kingdom, land, realm(noun) a domain in which something is dominant. 2  kingdom(noun) a country with a king as head of state. 3  kingdom, realm(noun) the domain ruled by a king or queen. 4  kingdom(noun) a monarchy with a king or queen as head of state.