Failure to Thrive

Failure to thrive is a medical term which denotes poor weight gain and physical growth failure over an extended period of time in infancy. Often abbreviated FTT, the term has been in medical use for over a century. As used by pediatricians, it covers poor physical growth of any cause and does not imply abnormal intellectual, social, or emotional development.
See more at Wikipedia.org...

Failure to thrive is used to describe a delay in a child's growth or development. [more]Failure to thrive - Community and Resources