ab·struse 
/əbˈstru:s/ adjective
/əbˈstru:s/ adjective [more abstruse; most abstruse] formal : hard to understand
▪ Her subject matter is abstruse. ▪ abstruse [=obscure] concepts/ideas/theories
▪ Her subject matter is abstruse. ▪ abstruse [=obscure] concepts/ideas/theories
— ab·struse·ly adverb
— ab·struse·ness noun [noncount]
