What is the origin of blossom?
Blossom in both the noun and the verb senses dates back to Old English. The Old English verb blōstmian “to bloom, blossom, effloresce” is a derivative of the noun blōstm, blōstma, blōsma “blossom, flower.” The English words blossom, bloom, and blow (“a yield or display of blossoms”) are all Germanic derivatives of the Proto-Indo-European root bhel-, bhlē-, bhlō– (and other variants) “to thrive, bloom.” In Latin the root appears in flōs (inflectional stem flōr-) “flower“ (which via Old French yields English flower, flour, and flourish). English florescent comes straight from Latin flōrescent-, the inflectional stem of flōrescēns, the present participle of flōrescere “to come into bloom.” Other English derivatives from Latin include floral and folium “leaf,” which becomes, again through Old French, English foil. Greek has the noun phýllon “leaf,” whose most common English derivative is probably chlorophyll.