One word substitution:

1.       A game in which in which no one wins - Drawn

2.      What cannot be heard - Inaudible

3.      One who knows many languages - Polyglot or multilingual

4.      A place where everything is perfect - Utopia

5.      A sweet music - Melody

6.      A person who is pure and clean - Immaculate

7.      To send back a person to one’s country - Repatriate

8.     One who tends to take a hopeful view of life - Optimist

9.      To be known for bad acts - Notorious

10.  Instruments to measure atmospheric pressure - Barometer