Meaning

noun British philosopher (born in Austria) who argued that scientific theories can never be proved to be true, but are tested by attempts to falsify them (1902-1994)

noun a container of stimulant drug (amyl nitrate or butyl nitrite)

noun a container for cooking popcorn

originFrom Middle English poppere, equivalent to pop + -er (suffix forming agent noun). Etymology 1 sense 8 ("capsule of amyl nitrite") is derived from the popping sound when the capsule is broken open; from which etymology 1 sense 9 also derives.

Etymology from Wiktionary, CC BY-SA 3.0