Sentence:  Some who have written on Utopia have treated it as `` a learned diversion of a learned world '' , `` a phantasy with which More amused himself '' , `` a holiday work , a spontaneous overflow of intellectual high spirits , a revel of debate , paradox , comedy and <WSD>invention</WSD> '' . 
Meaning of the word marked with <WSD> tags:  the act of inventing