What is the definition or description of: sudden infant death?

SIDS: SIDS is the unexplained death, usually during sleep, of a seemingly healthy baby less than a year old. SIDS is sometimes known as crib death because the infants often die in their cribs. To prevent it babies should sleep on their back, no blankets, bumpers or pillow, no stuffed animals in cribs, avoid second hand-smoking, avoid co-sleeping in same bed as parents.