This is the 1039th most frequent Spanish word.
desaparecido
"Desaparecido" means "missing" or "disappeared."
Here, 'desaparecido' is used as a past participle to indicate that the book is no longer present.
El libro que estaba en mi escritorio ha desaparecido misteriosamente.
The book that was on my desk has mysteriously disappeared.
In this sentence, 'desaparecida' describes the state of being missing or having vanished.
Han encontrado a la persona que estaba desaparecida desde hace semanas.
They have found the person who had been missing for weeks.
Here, 'desaparecido' functions as an adjective modifying 'man' (hombre), indicating the man is missing.