very thin, as thin as a hair
A fishing line made from hair.
The line along one's forehead where hair starts growing.
A very thin line in writing, drawing, or typography.
A very thin fissure.
Of an inappropriately or unusually low weight.
Being less invested in a particular area than market wisdom suggests.
Not too heavy for an intended purpose.
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.