"Betterings" is a somewhat antiquated word that is not used much in modern English. It refers to the act or process of making something better or improving it in some way. While there are not many direct synonyms for this word, some related words include "enhancement," "advancement," "amelioration," "upgrading," and "progression." These words express the same idea of improving something or making it better in some way. They can be used interchangeably with "betterings" in certain contexts, depending on the nuances of the sentence. Overall, there are many words in the English language that express the same concept as "betterings," despite the word being uncommonly used today.