Definition of Forcible detainer
A summary, speedy and adequate statutory remedy for obtaining possession of premises by one entitled to actual possession. Casa Grande Trust Co. v. Superior Court In and For Pinal County, 8 Ariz. App. 163, 444 P.2d 521, 523. Exists where one originally in rightful possession of realty refuses to surrender it at termination of his possessory right. Sayers & Muir Service Station v. Indian Refining Co., 266 Ky. 779, 100 S.W.2d 687, 689. Forcible detainer may ensue upon a peaceable entry, as well as upon a forcible entry; but it is most commonly spoken of in the phrase "forcible entry and detainer.” See also Ejectment; Eviction; Forcible entry and detainer; Process (Summary process).
That's the definition of Forcible detainer in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.