Pounds per square inch. The pound per square inch or, more accurately, pound-force per square inch (symbol: lbf/in2; abbreviation: psi) is a unit of pressure or of stress based on avoirdupois units. It is the pressure resulting from a force of one pound-force applied to an area of one square inch:
small for gesÂ·taÂ·tionÂ·al age. Infant whose birth weight is below the tenth percentile for gestational age. small for gestational age. SGA. 1. Term describing an infant whose birth weight is at or below the 10th percentile, as correlated with the number of weeks in utero on the intrauterine growth chart.
Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health. Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of his height in meters (kg/m2). The WHO definition is: 1  a BMI greater than or equal to 25 is overweight. 2  a BMI greater than or equal to 30 is obesity.