cunning: [13] Cunning did not always have its present-day negative connotations. At first it was a term of approval, meaning ‘learned’. It is connected in some way to the verb can, which originally meant ‘know’, although it is not altogether clear whether it is a direct use of the present participle of the English verb, or whether it was borrowed from the related Old Norse kunnandi, present participle of kunna ‘know’. Either way, it is a parallel formation to canny [16]. The sense ‘skilfully deceitful’ developed towards the end of the 16th century. => canny[cunning etymology, cunning origin, 英语词源]