pearl

pearl /ˈpɚl/ noun
plural pearls
pearl
/ˈpɚl/
noun
plural pearls
Britannica Dictionary definition of PEARL
1 
[count] : a hard, shiny, white ball that is formed inside the shell of an oyster and that is often used as jewelry
— see color picture on this page
2 
[noncount] : mother-of-pearl
3 
[count] : something that is shaped like a pearl
4 
[count] : someone or something that is very good or admired

cast/throw pearls before swine

: to give or offer something valuable to someone who does not understand its value

pearls of wisdom

: wise words or statements