"Billionths" refers to a minuscule fraction of a number, with a value of one billionth or 0.000000001. Other synonyms for "billionths" include "nanoseconds," "picoseconds," and "femtoseconds", which are terms used in the field of science to measure time intervals on a minuscule scale. Another synonym for "billionths" is "parts per billion," often used in chemistry to measure the concentration of a substance in a solution. Overall, these synonyms are crucial in describing small and precise measurements in various fields, from scientific research to commercial manufacturing.