spike (someone's) drink

Translations
подмешать что-то в напиток (кому-то)
He was arrested for trying to spike her drink at the party.
Его арестовали за попытку подмешать что-то в её напиток на вечеринке.
Definitions
To secretly add a substance, often a drug or alcohol, to someone's drink without their knowledge, typically with the intent to incapacitate or manipulate them.