可言

it may be said

can / may / able to / to approve / to permit / to suit / (particle used for emphasis) certainly / very

used in 可汗[ke4 han2]

words / speech / to say / to talk

too wonderful for words

can be understood, but not described (idiom, from Zhuangzi 莊子|庄子[Zhuang1 zi3]); mysterious and subtle

inexpressible (idiom)

can be understood, but not described (idiom, from Zhuangzi 莊子|庄子[Zhuang1 zi3]); mysterious and subtle