sly
(as) sly as a fox
Exceptionally clever, cunning, or shrewd, especially in devious or underhanded ways. He thought he was being sly as a fox in the way he had been skimming money from the cash registers, but management caught up with him eventually. The novel centers around the cat-and-mouse chase between a police detective and a thief who is as sly as a fox. She may come off as nothing but smiles and sunshine, but trust me—she's sly as a fox!
See also: fox, sly
a sly dog
Someone who, through cunning, devious, or dishonest means, achieves a fortuitous outcome. What a sly dog, he managed to get a copy of the test so he could memorize the answers ahead of time!
See also: dog, sly
on the sly
Secretly; in a clandestine or furtive manner. Even though he said he'd quit smoking, he still kept up the habit on the sly. The senator had been taking bribes from lobbyists on the sly for years before he was caught.
See also: on, sly
Farlex Dictionary of Idioms.
on the sly
Fig. secretly and deceptively. She was stealing little bits of money on the sly. Martin was having an affair with the maid on the sly.
See also: on, sly
*sly as a fox
and *cunning as a foxCliché smart and clever. (*Also: as ~.) My nephew is as sly as a fox. You have to be cunning as a fox to outwit me.
See also: fox, sly
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
on the sly
Furtively, secretly, as in She's always eating cookies on the sly. The adjective sly, which means "cunning" or "crafty," is here used as a noun. [c. 1800]
See also: on, sly
The American Heritage® Dictionary of Idioms by Christine Ammer.
do something on the ˈsly
do something secretly: She didn’t seem to have much appetite for dinner. I wonder if she’s been eating chocolates on the sly? OPPOSITE: (out) in(to) the openSee also: on, sly, something
Farlex Partner Idioms Dictionary
on the sly
mod. secretly and deceptively. She was stealing little bits of money on the sly.
See also: on, sly
sly
mod. excellent; cool. That is really a sly jacket you got there.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
on the sly
In a way intended to escape notice: took extra payments on the sly.
See also: on, sly
American Heritage® Dictionary of the English Language, Fifth Edition.
on the sly
Secretly, furtively. This early-nineteenth-century term appeared in a letter of John Keats’s (1818): “It might have been a good joke to pour on the sly bottle after bottle into a washing tub.” It remains current.
See also: on, sly
The Dictionary of Clichés by Christine Ammer
- (as) sly as a fox
- sly as a fox
- (as) wily as a fox
- (as) crafty as a fox
- fox
- crafty
- cunning
- (as) cunning as a fox
- every trick in the book
- a sly dog