Puericide is a word that refers to the act of killing one's own child. This is an incredibly severe and disturbing act, and as such, there are few synonyms that carry the same weight and connotations. However, some words that might be considered synonyms for puericide include filicide (killing one's own child), infanticide (killing a child in general), and neonaticide (killing a newborn). All of these words indicate a horrific and heinous act that is both illegal and universally condemned. It is important to note that these words should only be used in the most serious and appropriate contexts, and with great care.