schlau

Meaning

clever in a way that enables one to achieve one's goals; slightly sly or cunning (but not usually implying any evil intentions)
(informal) bright, intelligent, clever (with no such overtone at all)

cunning

sly

crafty

wily

shrewd

clever

foxy

astute

smart

canny

cautious

shifty

skillful

artful

cagey

calculating

dodgy

nimble

sharp

tricky

sneaky

cunningly

slick

leery

savvy

nifty

shrewdly

smartly

cute

cleverly

adroit

vulpinely

slily

cutely

dishonest

tactful

defiant

prudent

sophisticated

subtle

apt

able

accomplished

adept

capable

dexterous

handy

proficient

skilful

skilled

streetwise

bright

intelligent

quick-witted

sharp-witted

witty

alert

artfully

craftily

foxily

knavishly

slyly

trickily

uncandid

unworthy

sheisty

tricksy

archly

dexterously

on the sly

sneakingly

skilfully

Frequency

Pronounced as (IPA)

/ʃlaʊ̯/

Borrowed from Middle Low German slû, whence probably also Dutch sluw. Further origin uncertain. Probably from a Proto-Germanic *slūhaz (“sneaking, creeping”), perhaps ultimately from Proto-Indo-European *(s)leuǵ (“to crawl, slide”), if the original sense referred to sneaking and sliding. Related with Dutch sluiken (“to creep, smuggle, act clandestinely”). In spite of the near-identity in meaning and form, English sly is in all likelihood not related.