Definitions:

1. A thin explosive device inside an envelope or package and detonated when opened. NOUN
   • Bomb squads are trained to safely handle potential package bombs.
2. An explosive device concealed within or disguised as a package, such as a box, envelope, or parcel, that is typically mailed or delivered with the intent to harm or kill someone upon opening, handling, or delivery. NOUN
   • Authorities warned the public after a series of package bomb attacks.

Synonyms:

• booby trap
• I.E.D.
• letter bomb
• parcel bomb