bombast (n.) Look up bombast at Dictionary.com
1560s, "cotton padding," corrupted from earlier bombace (1550s), from O.Fr. bombace "cotton, cotton wadding," from L.L. bombacem, acc. of bombax "cotton, 'linteorum aut aliae quaevis quisquiliae,' " a corruption and transferred use of L. bombyx "silk," from Gk. bombyx "silk, silkworm" (which also came to mean "cotton" in Medieval Gk.), from some oriental word, perhaps related to Iranian pambak (modern panba) or Armenian bambok, perhaps ultimately from a PIE root meaning "to twist, wind." From stuffing and padding for clothes or upholstery, meaning extended to "pompous, empty speech" (1580s). Also from the same source are Swed. bomull, Dan. bomuld "cotton," and, via Turkish forms, Mod.Gk. mpampaki, Romanian bumbac, Serbo-Cr. pamuk. Ger. baumwolle "cotton" is probably from the Latin word but altered by folk-etymology to look like "tree wool." Pol. bawelna, Lith. bovelna are partial translations from German.