What it means
The beginning of words about two of something. bilateralby-LAT-er-ulHaving to do with both sides of the body.bi- twolater/o side-al relating toFull entry means both sides, the biceps muscle has two heads, a bicuspid valve has two flaps and bifocal glasses have two lenses. Do not mix it up with bi/o and bio-, a different root that means life, as in biology, biopsy and antibiotic.