poppy

The noun is derived from Late Middle English poppy, Middle English popy, popi, popie (“plant of the genus Papaver; poppy seeds used as a spice”) [and other forms], from Old English popiġ (“poppy”), Early Old English popeġ, popaeġ, popæġ, popei [and other forms], perhaps from Late Latin *papavum, popauer, from Latin papāver (“poppy”), which may be from a reduplication of Proto-Indo-European *péh₂wr̥ (“bonfire”). Doublet of papaver.

Sense 3 (“artificial poppy flower to remember those who died in the two World Wars and other armed conflicts”) reflects the efforts of American professor and humanitarian Moina Michael (1869–1944) to popularize the wearing of artificial poppies in remembrance of those who fought and died in World War I; she was inspired by the poem “In Flanders Fields” (1915) by the Canadian poet and soldier John McCrae (1872–1918): see the quotation.

The adjective is derived from the noun.

From pop (“loud, sharp sound; fizzy drink; to make or burst with a loud, sharp sound; to stand out”) +‎ -y (suffix forming adjectives with the sense ‘having the quality of’).

From pop(ular) +‎ -y (suffix forming adjectives with the sense ‘having the quality of’).

From pop (“affectionate form of father”) +‎ -y (suffix forming terms of endearment).