1
general::
Sleep outdoors; also, stay somewhere for an unusually long time. For example, "We camped out in a field this night" (George Washington, Journal, March 18, 1748). In the early 1900s, the expression was extended to figurative uses, meaning simply "to stay somewhere for an unusually long time," as in She camped out at the stage door, hoping for an autograph.
American Heritage Idioms
2
general::
Phrase(s): camp out
to live out of doors temporarily in a tent or camping vehicle, as on a vacation or special camping trip. • I love to camp out in the winter.
McGrawhill's American Idioms And Phrasal Verbs