The boondocks is an American expression that stems from the Tagalog word bundok. It originally referred to a remote rural area, but now it is often applied to an out-of-the-way city or town considered backward and unsophisticated. It can also designate a 'mountain'. 
The expression was introduced to English by U.S. military personnel fighting in the Philippine–American War (1899-1902). It derives from the Tagalog word "bundok", which means "mountain". According to military historian Paul A. Kramer, the term originally had "connotations of bewilderment and confusion", due to the guerrilla warfare in which the soldiers were engaged.
In the Philippines, the word bundok is also a colloquialism referring to rural inland areas, which are usually mountainous and difficult to access, as most major cities and settlements in the Philippines are located on or near the coastline. Equivalent terms include the Spanish-derived probinsiya ("province") and the Cebuano term bukid ("mountain"). When used generally, the term refers to a rustic or uncivilized area. When referring to people (taga-bundok or probinsiyano in Tagalog; taga-bukid in Cebuano; English: "someone who comes from the mountains/provinces"), it acquires a derogatory connotation of a stereotype of unsophisticated, ignorant, and illiterate country people.
The term has evolved into American slang used to refer to the countryside or any implicitly isolated rural/wilderness area, regardless of topography or vegetation. Similar slang or colloquial words are "the sticks", "the wops", "the chodes", "the backblocks", or "Woop Woop" in Australia and New Zealand, "bundu" in South Africa, and "out in the tules" in California. The diminutive "boonies" can be heard in films about the Vietnam War such as Brian De Palma's Casualties of War (1989) used by American soldiers to designate rural areas of Vietnam.
"Down in the Boondocks" is a 1965 hit Billy Joe Royal song written and produced by Joe South. It tells the story of a young man who laments that people put him down because he was born in the boondocks. He is in love with the boss man's daughter and vows to work slavishly until, one day, he can "move from this old shack" and fit in with her society. Throughout the song, he asks that the "Lord have mercy on the boy from down in the boondocks".
- Williams, Edwin B., ed. (September 1991). The Scribner-Bantam English Dictionary (Revised ed.). Bantam Books. p. 105. ISBN 0-553-26496-6.
- The American Heritage Dictionary of the English Language. Boston: Houghton Mifflin.
- Clay, Grady (1998). "Boondocks". Real Places. Chicago: University of Chicago Press. pp. 180–181. ISBN 0-226-10949-6.
- Kramer, Paul (2006). The Blood of Government. Chapel Hill: University of North Carolina Press. pp. 33–34. ISBN 0-8078-5653-3.
- Heller, Louis (1984). "boondocks". The Private Lives of English Words. London: Routledge & Kegan Paul. p. 20. ISBN 0-7102-0006-4.
- Brock, Emily K. "Emily K. Brock. Bundok—Filipino". Environment & Society Portal. Rachel Carson Center for Environment & Society. Retrieved 21 May 2014.
- "What A English" by Jon Joaquin.[dead link]
- Competence Matters: the Peter Principle Strikes the Philippines Over and Over