piston piston /ˈpɪstən/

noun

1. Mechanical device that has a plunging or thrusting motion  ( piston , plunger )
   mechanical device that has a plunging or thrusting motion
   
   

 Piston

1. United States neoclassical composer (1894-1976)  ( Piston , Walter Piston )
   United States neoclassical composer (1894-1976)
   

 antihero antihero /ˈæntiːˈhɪroʊ/

noun

1. A protagonist who lacks the characteristics that would make him a hero (or her a heroine)  ( antihero )
   a protagonist who lacks the characteristics that would make him a hero (or her a heroine)
    The novel's antihero, though flawed, captivated readers with his complex nature.
   The novel's antihero, though flawed, captivated readers with his complex nature.
   
   

 gramophone gramophone /ˈɡræməˌfoʊn/

noun

1. An antique record player; the sound of the vibrating needle is amplified acoustically  ( acoustic gramophone , gramophone )
   an antique record player; the sound of the vibrating needle is amplified acoustically
   
   

 densimeter densimeter /dɛnˈsɪmɪtər/

noun

1. A measuring instrument for determining density or specific gravity  ( densimeter , densitometer )
   a measuring instrument for determining density or specific gravity