What is the meaning of Shenanigan?

singular of shenanigans: a deceitful confidence trick; also, an act of mischief; a prank, a trick; an act of mischievous play, especially by children.

Dishonest, underhanded, or unscrupulous activities or behaviour; skulduggery, trickery; also, mischievous behaviour or play; high jinks.

To play a deceitful confidence trick on (someone); to swindle, to trick; also, to carry out an act of mischief on (someone); to prank.

To play a deceitful confidence trick; also, to carry out an act of mischief.

Source: wiktionary.org