Definition

1. Adverb:
   • In a secretive, furtive, or stealthy manner: The phrase "on the sly" describes an action done secretly to avoid being noticed, often because it is considered wrong, improper, or against the rules.

Usage

• "On the sly" is an adverbial phrase used to modify a verb, indicating the manner in which an action is performed. It implies deception or concealment.
• It is typically used in informal contexts.

Examples

• Adverb:
  • He was eating cookies on the sly while his mother wasn't looking.
  • They met on the sly to plan the surprise party.
  • The employee checked his personal email on the sly during work hours.

Advanced Usage

• The phrase often carries a connotation of doing something that is mildly mischievous, forbidden, or socially disapproved.
  • She had a cigarette on the sly, even though she was trying to quit.

Variants and Related Words

• Slyly (adverb): In a cunning or deceitful manner. (e.g., )
• Sly (adjective): Having or showing a cunning and deceitful nature. (e.g., )

Synonyms

• Secretly: In a way that is kept hidden or not known by others.
• Furtively: In a way that attempts to avoid notice or attention, typically because of guilt or a belief that discovery would lead to trouble.
• Stealthily: In a cautious and surreptitious manner, so as not to be seen or heard.
• Covertly: Without being openly acknowledged or displayed; secretly.

Related Phrases

• On the quiet: An informal phrase with a very similar meaning to "on the sly," implying doing something secretly.
  • He made the deal on the quiet.
• Behind someone's back: Secretly and deceitfully, especially in a way that is disloyal.
  • She criticized him behind his back. (This has a stronger negative connotation of betrayal.)

Idioms

• While "on the sly" is itself an idiomatic phrase, it is not typically part of a larger, fixed idiom. Its meaning is contained within the phrase itself.

Adverb

1. in a furtive manner
   • the soldiers were furtively crawling through the night