sly

Word family

• slyly
  adverbB2
• slyness
  nounC1

Synonym discussion

Sense: adjective/1

All four words describe someone who uses cleverness to get an advantage, but they differ in nuance. Cunning is the broadest term — it suggests sharp, calculated intelligence applied to deception (a cunning plan to avoid taxes). Crafty emphasises skill and ingenuity in carrying out schemes (a crafty lawyer who finds loopholes). Sneaky is the most informal and carries a playground tone — it stresses secrecy and the fact that the action goes unnoticed (a sneaky look at someone else's test answers). Wily has an older, slightly literary flavour and suggests experience-based trickery, often in a long-term game (a wily old fisherman who knows every hiding spot). Use sly when the deception involves a surface appearance of innocence or friendliness that masks self-interest. For example: 'The sly neighbour brought over cookies while secretly checking which houses were empty for the weekend.'

Common collocations

Etymology

Sly comes from Old Norse slœgr, meaning 'cunning' or 'skillful at trickery'. It entered English through Viking influence on northern dialects during the medieval period. The original sense of cleverness in a negative, deceptive way has stayed remarkably stable over a thousand years — though the lighter sense (a sly smile, meaning knowing or mischievous) developed later in the 1700s. The word is related to sleight, as in 'sleight of hand', which shares the same root idea of nimble skill.