15-Letter Words Starting: UL

• using the reflections of high-frequency sound waves to construct an image of a body organ (a sonogram); commonly used to observe fetal growth or study bodily organs

• light microscope that uses scattered light to show particles too small to see with ordinary microscopes

• a high speed centrifuge used to determine the relative molecular masses of large molecules in high polymers and proteins

• subject to the action of an ultracentrifuge

• (Roman Catholic Church) the policy that the absolute authority of the church should be vested in the pope