celda

prison cell; cell

“La policía me dijo que mi marido falleció tras ahorcarse con una manta en la celda” — The police told me that my husband died after hanging himself with a sheet in the prison cell

Borrowed from Latin cella, with the -ld- arising from the effort of pronouncing a double Latin -ll- at the time (cf. rebelde). Compare the inherited doublet cilla, from Old Spanish ciella.