The Collaborative International Dictionary of English v.0.48:
Decamp \De*camp"\, v. i. [imp. & p. p. Decamped (?; 215); p.
pr. & vb. n. Decamping.] [F. d['e]camper; pref. d['e]- (L.
dis) + camp camp. See Camp.]
1. To break up a camp; to move away from a camping ground,
usually by night or secretly. --Macaulay.
2. Hence, to depart suddenly; to run away; -- generally used
The fathers were ordered to decamp, and the house
was once again converted into a tavern. --Goldsmith.