What is shenanigans and malarkey?

Shenanigans and malarkey are both informal American English slang terms that mean nonsense, mischief, dishonest behavior, or foolish talk, but they have slightly different nuances and origins. Shenanigans, pronounced she-nan-i-gans, refers to playful mischief, pranks, trickery, or secret dishonest activity, often with a sense of mischievous or underhanded behavior, for example kids getting up to shenanigans after midnight or political shenanigans meaning shady dealings. It is plural and often used to describe lighthearted trouble or deceitful maneuvers. The origin is uncertain but likely from Irish or German, first appearing in American English in the mid-19th century. Malarkey, also spelled malarky, pronounced ma-lar-key, means nonsense, foolish talk, or exaggerated lies, often used to dismiss something as untrue or absurd, for example that's a bunch of malarkey meaning that's nonsense. It is associated with Irish-American slang and was popularized in the 1920s-30s, famously used by cartoon character and later by President Joe Biden who frequently says that's malarkey. When used together as shenanigans and malarkey, the phrase emphasizes both mischievous actions and nonsensical talk, often to criticize someone's behavior as both deceitful and foolish. Both are informal, mildly humorous, not highly offensive, and commonly used in American politics and everyday conversation to call out dishonesty or silliness.