A 1988 study counted 109 definitions of terrorism that covered a total of 22 different definitional elements.
In the same study another source:
Terrorism expert Walter Laqueur also has counted over 100 definitions and concludes that the “only general characteristic generally agreed upon is that terrorism involves violence and the threat of violence.”
Quibblers refer to:
Alex P. Schmid, Albert J. Jongman, et al., Political Terrorism: A New Guide to Actors, Authors, Concepts, Data Bases, Theories, and Literature, New Brunswick, NJ: Transaction Books, 1988, pp. 5-6.
Or:
Walter Laqueur, The New Terrorism: Fanaticism and the Arms of Mass Destruction, New York: Oxford University Press, 1999, p. 6.
More succinctly, Dictionary.comsays:
ter·ror·ism [ter-uh-riz-uhm] noun
1. the use of violence and threats to intimidate or coerce, especially for political purposes.
2. the state of fear and submission produced by terrorism or terrorization.
3. a terroristic method of governing or of resisting a government.
"Especially for political purposes..." don't make it necessarily so.
For a political definition, check out the U.S. Department of Defense:
The United States Department of Defense defines terrorism as “the calculated use of unlawful violence or threat of unlawful violence to inculcate fear; intended to coerce or to intimidate governments or societies in the pursuit of goals that are generally political, religious, or ideological.” Within this definition, there are three key elements—violence, fear, and intimidation—and each element produces terror in its victims. The FBI uses this: "Terrorism is the unlawful use of force and violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives." The U.S. Department of State defines "terrorism" to be "premeditated politically-motivated violence perpetrated against non-combatant targets by sub-national groups or clandestine agents, usually intended to influence an audience.
Merriam Webster states it simply:
the systematic use of terror especially as a means of coercion
To me anyone who terrorizes is a terrorist:
Verb 1. terrorize - coerce by violence or with threats
terrorise
coerce, force, hale, pressure, squeeze - to cause to do through pressure or necessity, by physical, moral or intellectual means :"She forced him to take a job in the city"; "He squeezed her for information"
2. terrorize - fill with terror; frighten greatly
terrify, terrorise
affright, fright, frighten, scare - cause fear in; "The stranger who hangs around the building frightens me"; "Ghosts could never affright her"
panic - cause sudden fear in or fill with sudden panic; "The mere thought of an isolation cell panicked the prisoners"
terrorize
verb
1. bully, menace, intimidate, threaten, oppress, coerce, strong-arm (informal), browbeat In his childhood he liked to terrorize his young siblings.
2. terrify, alarm, frighten, scare, intimidate, petrify, scare to death, strike terror into, put the fear of God into, fill with terror, scare the bejesus out of (informal), frighten out of your wits, inspire panic in The government had the helicopter gunships to terrorize the population.
Therefore, by extension, a bully can be a terrorist.
Quibble away, word terrorists. Or, perhaps a more politically correct term might be "word browbeaters".