AU AU /ˈoʊ/

noun

1. A unit of length used for distances within the solar system; equal to the mean distance between the Earth and the Sun (approximately 93 million miles or 150 million kilometers)  ( AU , Astronomical Unit )
   a unit of length used for distances within the solar system; equal to the mean distance between the Earth and the Sun (approximately 93 million miles or 150 million kilometers)
   

 Au

1. A soft yellow malleable ductile (trivalent and univalent) metallic element; occurs mainly as nuggets in rocks and alluvial deposits; does not react with most chemicals but is attacked by chlorine and aqua regia  ( atomic number 79 , Au , gold )
   a soft yellow malleable ductile (trivalent and univalent) metallic element; occurs mainly as nuggets in rocks and alluvial deposits; does not react with most chemicals but is attacked by chlorine and aqua regia
    He trained for years to win the gold medal in the all-around competition
   He trained for years to win the gold medal in the all-around competition
   
   

 head restraint head restraint /hɛd rɪˈstreɪnt/

noun

1. A cushion attached to the top of the back of an automobile's seat to prevent whiplash  ( head restraint , headrest )
   a cushion attached to the top of the back of an automobile's seat to prevent whiplash
    Adjusting the headrest can help prevent neck injuries in the event of a collision
   Adjusting the headrest can help prevent neck injuries in the event of a collision
   
   

 Donatello Donatello /ˌdɒnəˈtɛloʊ/

noun

1. Florentine sculptor famous for his lifelike sculptures (1386-1466)  ( Donatello , Donato di Betto Bardi )
   Florentine sculptor famous for his lifelike sculptures (1386-1466)
   
   

 northern pocket gopher northern pocket gopher /ˈnɔːrθərn ˈpɑːkɪt ˈgoʊfər/

noun

1. Greyish to brown gopher of western and central United States  ( northern pocket gopher , Thomomys talpoides )
   greyish to brown gopher of western and central United States