before vowels myel-, word-forming element meaning "marrow, spinal cord," from Greek myelos "marrow; the brain," a word of unknown origin.

"a word of several syllables," 1560s; see poly- "many" + syllable. As a rule, a word of more than three syllables.

before vowels morph-, word-forming element of Greek origin meaning "form, shape," from Greek morphē "form, shape; beauty, outward appearance," a word of uncertain etymology.

"shirt, chemise, body garment of linen or cotton for either sex," Middle English serk, late Old English serc "shirt, corselet, coat of mail," surviving as a Scottish and northern dialect word. It is either the Old English word influenced in pronunciation and spelling by its Old Norse cognate serkr, or that word in place of the native one. A general Germanic word (see shirt and also compare berserk.

word-forming element in medicine meaning "a vein or veins," from Greek phlebo-, combining form of phleps "vein," a word of uncertain origin.

also back formation, "word formed from an existing word, often by removal of a suffix or supposed suffix," by 1887, from back (adv.) + formation.

"a word of many syllables," by 1818 as a dictionary word, from multi- "many" + syllable. As an adjective, "consisting of or containing many syllables," by 1892.