Final answer:
SIDS stands for Sudden Infant Death Syndrome, which is the abbreviation for an infant who suddenly dies from unknown causes.
Step-by-step explanation:
The abbreviation for an infant who suddenly dies from unknown causes is SIDS, which stands for Sudden Infant Death Syndrome. SIDS is a medical term used to describe the unexplained death of an infant under one year old. It is a tragic event that typically occurs during sleep and is characterized by the absence of any signs of illness or distress.
Learn more about Sudden Infant Death Syndrome (SIDS)