(21) An oligarchy is the supremacy of the rich in a state.
(22) A citizen is one who is qualified to exercise deliberative and judicial functions.
(23) Length is that dimension of a solid which would be measured by the longest line.
(24) An eccentricity is a peculiar idiosyncrasy.
(25) Deliberation is that species of investigation which is concerned with matters of action.
(26) Memory is that which helps us to forget.
(27) Politeness is the oil that lubricates the wheels of society.
(28) An acute-angled triangle is one which has an acute angle.
(29) A cause is that without which something would not be.
(30) A cause is the invariable antecedent of a phenomenon.