The kanji is threat and the noun version (here) is threat or a threat.
Curious about the difference between 脅し and 脅迫? Both involve threats or intimidation, but the key distinction is the level of severity. 脅し is generally associated with milder forms of intimidation and coercion, while 脅迫 entails more direct and serious threats that may even break the law.
Think about a threat being sent to you. It's in the form of bad odor (おど). Yuck, what a nasty way to send a threat.
On the way to the sushi bar I got a threat that said I’ll be murdered if I put soy sauce on my sushi.