equality, fairness

公平(こうへい) Fair.   $$$PPP
 
平等(びょうどう) Even-steven. (To cut the cake into equal pieces, to treat your adopted kids and your biological kids equally.)   PPP
 
等量(とうりょう) Equal amount – usually used in math or science.   TTT
 
同等(どうとう) A more casual form of 等量. Means equal, equivalent. 同等 does not have the moral judgment of, say, 公平.  ‘This engine does the work of 4 horses’; ‘I have the strength of a dozen oxen!’    SITU
 
均等(きんとう) (not used in daily life). Uniform. Uniform size or shape. Uniform distribution.  When I die, I want my son and daughter to get the same amount of land.    SITU
 
等しい(ひとしい) Mathematically equivalent. Unlike the other ‘equivalent’ words, 等しい can used figuratively, as in, “He’s as good as dead!” “Your lies are tantamount to treason, and I’ll see you hanged!!” 等しい can also be used to mean ‘to look similar or identical’ . In this sense, 等しい  is closer to 同じ than 公平。 But it’s a little more formal.