a device for showing the operating condition of some system
a signal for attracting attention
(chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction
a glass or plastic vessel used for storing drinks or other liquids; typically cylindrical without handles and with a narrow neck that can be plugged or capped
a vessel fitted with a flexible teat and filled with milk or formula; used as a substitute for breast feeding infants and very young children
throw into great confusion or disorder; "Fundamental Islamicists threaten to perturb the social order in Algeria and Egypt"
disturb in mind or make uneasy or cause to be worried or alarmed; "She was rather perturbed by the news that her father was seriously ill"
cause a celestial body to deviate from a theoretically regular orbital motion, especially as a result of interposed or extraordinary gravitational pull; "The orbits of these stars were perturbed by the passings of a comet"
disturb or interfere with the usual path of an electron or atom; "The electrons were perturbed by the passing ion"