Sabbath Sabbath /ˈsæbəθ/

noun

1. () A day of rest and worship: Sunday for most Christians; Saturday for the Jews and a few Christians; Friday for Muslims  ( Sabbath )
   a day of rest and worship: Sunday for most Christians; Saturday for the Jews and a few Christians; Friday for Muslims
    The community gathered in the church on the Sabbath to rest and pray together.
   The community gathered in the church on the Sabbath to rest and pray together.
   
   

 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)
   

 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
   
   

 ballet mistress ballet mistress /ˈbæleɪ ˈmɪstrɪs/

noun

1. A woman who directs and teaches and rehearses dancers for a ballet company  ( ballet mistress )
   a woman who directs and teaches and rehearses dancers for a ballet company
    The ballet mistress worked diligently to prepare the dancers for their upcoming performance.
   The ballet mistress worked diligently to prepare the dancers for their upcoming performance.