(n.) A locked box in which one keeps one's ghosts safe from the world. Alternatively: a locked box in which one locks ghosts to keep the world safe from one's ghosts.
(adj.) To be in a state of immunity or irrelevance to ghosts.
(prop. n.) A failed and forgotten product consisting of an atomized ghost repellent which renders the subject ghostsafe (def. 2)
(slang, nonsense) A phonetic anagram of Ghostface.