Choose the appropriate word which can be substituted for the given sentence: $A$ government by the nobles.

Choose the appropriate word which can be substituted for the given sentence: $A$ person who remains confident or hopeful about the success of something.

Choose the appropriate word which can be substituted for the given sentence: 'One who cannot be corrected'.

Choose the appropriate word which can be substituted for the given sentence: 'One who dabbles in fine arts for the love of it and not for monetary gains'.

Choose the appropriate word which can be substituted for the given sentence: The sound made by a camel.

Choose the appropriate word which can be substituted for the given sentence: 'The practice of having several wives'.