13-Letter Words Ending: OPES

• an instrument that indicates whether two periodic motions are synchronous (especially an instrument that enables a pilot to synchronize the propellers of a plane that has two or more engines)

• a slender tubular instrument used to examine the bronchial tubes

• a complex pattern of constantly changing colors and shapes

• an optical toy in a tube; it produces symmetrical patterns as bits of colored glass are reflected by mirrors

• A device used to detect electric currents, particularly one using the deflection of a magnetic needle.

• a medical instrument for examining the larynx

• an optical instrument for spectrographic analysis

• measuring instrument that detects electric charge; two gold leaves diverge owing to repulsion of charges with like sign

• electronic equipment that provides visual images of varying electrical quantities

• a radioactive isotope of an element; produced either naturally or artificially