(music, historical, US) A group of classical-music composers who lived during the late-19th and early-20th centuries in New England, based in and around Boston, Massachusetts.

(history, uncommon) World War II defined as starting from the Manchurian Incident of September 18, 1931 to Imperial Japan’s surrender in September 1945.

plural of chief petty officer second class

(Canada, Navy) A warrant officer in the Canadian Forces Maritime Command, ranking above petty officer first class and below chief petty officer first class.

plural of perpetual motion machine of the second kind

(physics, pseudoscience) A perpetual motion machine that spontaneously converts thermal energy into mechanical work.