不易 bùyì HSK5 difficult Origin Definitions Defs Strokes Stroke Words Sentences Sents 来之不易 láizhībùyì hard-won hard to come by; not easily obtained不易之论 bùyìzhīlùn unalterable truth a perfectly sound proposition or argument that is considered irrefutable and final实属不易 shíshǔbùyì truly difficult truly difficult; no easy feat (idiom)