We speak of a knowing rascal, meaning cunning or shrewd within a narrow range, but of a knowing horse or dog, in the sense of sagacious, implying that he knows more than could be expected of such an animal.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

cunning Tuaregs have a reputation for bravery and cunning.
ingenious The ingenious boy won a prize for his invention.
astute Tom was an astute businessman who made a lot of money.
wily He plays a wily detective with a penchant for disguises.

Popularity over time

Word	1850 → 2019	Trend
shrewd		steady
cunning		rising
ingenious		falling
astute		rising
wily		rising

Use in printed books, per decade from 1850 to 2019.

By length

3 letters: sly¹
4 letters: cute¹, keen¹, sage¹, wily²
5 letters: quick¹, smart¹, sharp¹, canny²
6 letters: clever², subtle², crafty², astute², artful²
7 letters: knowing², cunning²
8 letters: profound², scheming²
9 letters: ingenious³, conniving³, sagacious
10 letters: discerning³
11 letters: intelligent⁴, calculating⁴, penetrating⁴, calculative
13 letters: perspicacious⁴

The small number after each word is its number of syllables (wily² = 2 syllables).

In other languages

Français: futé
Español: pícaro
Deutsch: schlau