the closure (literally, "lock") for a letter or a piece of writing (see Molina)
Orthographic Variants:
amatlacuiloltzaqualiztli
Alonso de Molina:
amatlacuiloltzaqualiztli. cerradura de carta, o de escriptura. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 4v. col. 2. Thanks to Joe Campbell for providing the transcription.