> You should need to know the meaning of the word to play it
How would you go about determining in a regulated fashion whether someone knows the meaning of a word?
Would you have them offer a definition to be checked against an official dictionary?
Would the definition given have to match the official dictionary definition word for word?
Is so, wouldn't this simply force high-level scrabble players to memorize not only the official words but the official meanings themselves?
And if perfect matching wouldn't be required, how much variation would be allowed and how would such variation be measured?
There's no sense in falling back on the "just use the word in a sentence" proof, either. Because that's no proof at all, since, even if we dispense with all the problems consensus introduces, if the usage is contested, then some official dictionary definition will have to be referenced in the end.
And then you're going to have to deal with the above mentioned issues anyways.
The desire for a more natural, simple and organic Scrabble world in which any word played must be theoretically backended by a player's knowledge of its definition is, well, just asking for trouble.