What is the meaning of Underweight?

Of an inappropriately or unusually low weight.

Not too heavy for an intended purpose.

Being less invested in a particular area than market wisdom suggests.

The state or quality of being underweight.

An underweight person.

An underweight investment.

To underestimate the weight of.

To give insufficient weight to (a consideration); to underestimate the importance of.

To invest in less than conventional wisdom would dictate.

Source: wiktionary.org