Original (pre-Orwellian) Definition of the Word "Terrorism" Funk and Wagnalls New Practical Standard Dictionary (1946)
18 U.S.C. Part I, Chapter 113B: Terrorism- federal crimes relating to terrorism
28 CFR 0.85 FBI, General Functions
Title 28: Judicial Administration
PART 0—ORGANIZATION OF THE DEPARTMENT OF JUSTICE
(l) Exercise Lead Agency responsibility in investigating all crimes for which it has primary or concurrent jurisdiction and which involve terrorist activities or acts in preparation of terrorist activities within the statutory jurisdiction of the United States. Within the United States, this would include the collection, coordination, analysis, management and dissemination of intelligence and criminal information as appropriate. If another Federal agency identifies an individual who is engaged in terrorist activities or in acts in preparation of terrorist activities, that agency is requested to promptly notify the FBI. Terrorism includes 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.
Black's Law Dictionary, Sixth Edition, page 1473:
terrorism. "Act of terrorism" means an activity that involves a violent act or an act dangerous to human life that is a violation of the criminal laws of the United States or of any State, or that would be a criminal violation if committed within the jurisdiction of the United States or of any State; and appears to be intended--(i) to intimidate or coerce a civilian population; (ii) to influence the policy of a government by intimidation or coercion, or (iii) to affect the conduct of a government by assassination or kidnapping. 18 U.S.C.A. §3077.
Webster's Ninth New Collegiate Dictionary, 1983, ISBN 0-87779-509-6, page 1218:
terrorism. the systematic used of terror esp. as a means of coercion.
Webster's Ninth New Collegiate Dictionary, 1983, ISBN 0-87779-509-6, page 1218:
terror : 1: a state of intense fear. 2 a: one that inspires fear and anxiety: WORRY b: an appalling person or thing esp: BRAT 3: REIGN OF TERROR 4: violence (as bomb-throwing) committed by groups in order to intimidate a population or government into granting their demands, insurrection and revolutionary~. syn see FEAR.
Click here to see the USA Patriot Act, which provides stiff punishments for terrorism.
Chief of Naval Education and Training (CNET) Terrorism Training
Click here to see the Chief of Naval Education and Training (CNET) official training curriculum that defines terrorism from the perspective of the U.S. government.
SEC. 802. DEFINITION OF DOMESTIC TERRORISM.
(a) DOMESTIC TERRORISM DEFINED- Section 2331 of title 18, United States Code, is amended--
(1) in paragraph (1)(B)(iii), by striking `by assassination or kidnapping' and inserting `by mass destruction, assassination, or kidnapping';
(2) in paragraph (3), by striking `and';
(3) in paragraph (4), by striking the period at the end and inserting `; and'; and
(4) by adding at the end the following:
`(5) the term `domestic terrorism' means activities that--
`(A) involve acts dangerous to human life that are a violation of the criminal laws of the United States or of any State;
`(B) appear to be intended--
`(i) to intimidate or coerce a civilian population;
`(ii) to influence the policy of a government by intimidation or coercion; or
`(iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and
`(C) occur primarily within the territorial jurisdiction of the United States.'.
(b) CONFORMING AMENDMENT- Section 3077(1) of title 18, United States Code, is amended to read as follows:
`(1) `act of terrorism' means an act of domestic or international terrorism as defined in section 2331;'.
TITLE 18 > PART I > CHAPTER 113B > § 2331 http://www.law.cornell.edu/uscode/html/uscode18/usc_sec_18_00002331----000-.html
§ 2331. Definitions
(5) the term “domestic terrorism” means activities that—
(A) involve acts dangerous to human life that are a violation of the criminal laws of the United States or of any State;
(B) appear to be intended—
(i) to intimidate or coerce a civilian population;
(ii) to influence the policy of a government by intimidation or coercion; or
(iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and
(C) occur primarily within the territorial jurisdiction of the United States.
TITLE 18 > PART II > CHAPTER 204 > § 3077
§ 3077. Definitions
As used in this chapter, the term—
(1) “act of terrorism” means an act of domestic or international terrorism as defined in section 2331;
TITLE 18 > PART II > CHAPTER 204 > § 3071
§ 3071. Information for which rewards authorized
(a) With respect to acts of terrorism primarily within the territorial jurisdiction of the United States, the Attorney General may reward any individual who furnishes information—
(1) leading to the arrest or conviction, in any country, of any individual or individuals for the commission of an act of terrorism against a United States person or United States property; or
(2) leading to the arrest or conviction, in any country, of any individual or individuals for conspiring or attempting to commit an act of terrorism against a United States person or property; or
(3) leading to the prevention, frustration, or favorable resolution of an act of terrorism against a United States person or property.
(b) With respect to acts of espionage involving or directed at the United States, the Attorney General may reward any individual who furnishes information—
(1) leading to the arrest or conviction, in any country, of any individual or individuals for commission of an act of espionage against the United States;
(2) leading to the arrest or conviction, in any country, of any individual or individuals for conspiring or attempting to commit an act of espionage against the United States; or
(3) leading to the prevention or frustration of an act of espionage against the United States.
FBI Literature says Constitutionalists are terrorists:
The Federal Bureau of
Investigation labels all those persons who insist on observance of
government employees to the U.S. Constitution as "super patriots"
and terrorists! 
Click
here to read the FBI's own pamphlet that says this.