WordNet (r) 3.0 (2006):

infant mortality
    n 1: the death rate during the first year of life [syn: infant
         deathrate, infant mortality, infant mortality rate]

The Jargon File (version 4.4.7, 29 Dec 2003):

infant mortality
 n.

    It is common lore among hackers (and in the electronics industry at large;
    this term is possibly techspeak by now) that the chances of sudden hardware
    failure drop off exponentially with a machine's time since first use (that
    is, until the relatively distant time at which enough mechanical wear in I/
    O devices and thermal-cycling stress in components has accumulated for the
    machine to start going senile). Up to half of all chip and wire failures
    happen within a new system's first few weeks; such failures are often
    referred to as infant mortality problems (or, occasionally, as sudden
    infant death syndrome). See bathtub curve, burn-in period.


The Free On-line Dictionary of Computing (30 December 2018):

infant mortality

    It is common lore among hackers (and in the
   electronics industry at large) that the chances of sudden
   hardware failure drop off exponentially with a machine's time
   since first use (that is, until the relatively distant time at
   which enough mechanical wear in I/O devices and
   thermal-cycling stress in components has accumulated for the
   machine to start going senile).  Up to half of all chip and
   wire failures happen within a new system's first few weeks;
   such failures are often referred to as "infant mortality"
   problems (or, occasionally, as "sudden infant death
   syndrome").

   See bathtub curve, burn-in period.

   [Jargon File]

   (1995-03-20)