FTT
Failure to thrive.
Refers to a child whose physical growth is significantly less than that of peers.
There is no official consensus on what constitutes FTT.
It usually refers to a child whose growth is below the 3rd or 5th percentiles for their age or whose growth has fallen off precipitously and crossed two major growth percentiles (for example, from above the 75th percentile to below the 25th percentile).