Definitions for "Underweight"
When stock in an investment portfolio has less exposure to a specific sector, in comparison to a neutral or benchmark position.
The anthropometric index 'weight-for-age' represents body mass relative to age. Weight-for-age is influenced by the height of the child and his or her weight and is thus a composite of stunting and wasting (which makes its interpretation difficult). In the absence of wasting, both weight-for-age and height-for-age reflect the long term nutrition and health experience of the individual or population. General lightness in weight refers to a child having a low weight-for-age. Lightness may represent either normal variation or a deficit. Underweight specifically refers to lightness that is a deficit and is defined as low weight-for-age, i.e.; below 2 standard deviations (or 2 Z-scores) of the median value of the National Center for Health Statistics/World Health Organization International Growth Reference for weight-for-age.
the percent of children 0 through 4 years who are below 2 standard deviations weight-for-age by NCHS/WHO standards is the prevalence of child malnutrition.
having unattractive thinness; "a child with skinny freckled legs"; "a long scrawny neck"
Having slightly less than your usual percent allocation in a stock or mutual fund to protect yourself from below average growth.