Sentence:  A single 24 - hr composite sample had a BOD of 260 mg / <WSD>l</WSD> , indicating a typical domestic sewage . 
Meaning of the word marked with <WSD> tags:  a metric unit of capacity, formerly defined as the volume of one kilogram of pure water under standard conditions; now equal to 1,000 cubic centimeters (or approximately 1.75 pints)