Pronunciation: [kˈaltɹɒp] (IPA) 
Caltrop is a noun that refers to a small, four-pointed metal or plastic object used as a weapon or a deterrent against vehicles. The word is spelled with a "c" at the beginning, followed by an "a," then "l," "t," "r," "o," and "p." The phonetic transcription for caltrop is /ˈkæltrəp/, with the stress on the second syllable (KAL-trop). The word's etymology comes from the Latin word "calcitrapa," which means "foot trap."
A caltrop is a small, sharp object typically made of metal with four points or spikes, arranged in such a way that one point is always upright when thrown or dropped on the ground. Each of the four points usually has three sides, resembling a three-dimensional tetrahedron shape. Caltrops were historically used as offensive weapons and tactical devices to impede or disable infantry, cavalry, or vehicles.
The purpose of a caltrop is to disrupt movement, primarily by puncturing and damaging the tires or hooves of the targeted subjects. When thrown onto the ground or dispersed across a path, a caltrop can effectively create a hazardous environment, rendering it difficult or impossible for enemies or obstacles to proceed. Caltrops are particularly effective against wheeled vehicles, horses, or foot soldiers, as the sharp points can penetrate their soft surfaces and inflict damage or injury.
The origin of caltrops can be traced back to ancient times, where they were frequently used in warfare. Today, caltrops continue to be employed by various military or law enforcement agencies to immobilize or incapacitate opponents. Additionally, they can be utilized for defensive purposes to create barriers or obstacles, effectively controlling access or protecting valuable assets.
The word "caltrop" originated from the Late Latin term "calcatrippa", which was a combination of the Latin words "calx" meaning "heel" and "trip" meaning "foot". It referred to a device made of spikes or iron bars arranged in such a way that, regardless of how it was thrown on the ground, one spike would always be pointing upwards. This design allowed the caltrop to hinder or stop the progress of horses, soldiers, or vehicles by piercing their feet or hooves, hence the combination of "calx" and "trip" in the name. Over time, "calcatrippa" evolved into "caltrop" in English.
