Merriam-Webster Collegiate Dictionary - filibuster

 I. noun  Etymology: Spanish ~o, literally, freebooter  Date: 1851  1. an irregular military adventurer; specifically an American engaged in fomenting insurrections in Latin America in the mid-19th century  2. ~ (II)  a. the use of extreme dilatory tactics in an attempt to delay or prevent action especially in a legislative assembly  b. an instance of this practice  II. verb  (-tered; ~ing)  Date: 1851  intransitive verb  1. to carry out insurrectionist activities in a foreign country  2. to engage in a ~  transitive verb to subject to a ~  • ~er noun