Manifold
Old English manigfeald ; current noun senses date from the mid 19th century.
wiktionary
From Middle English manifold, from Old English maniġfeald(“manifold, various, varied, complicated, numerous, abundant, plural”), from Proto-Germanic *managafalþaz, equivalent to many + -fold. Cognate with Middle High German manecvalt(“manifold”), Icelandic margfaldr(“multiple”). Compare also German mannigfaltig(“various”), Dutch menigvoudig(“various”), Danish mangefold(“multiple”), Swedish mångfald(“diversity”).
From Middle English manifolden, from Old English maniġfealdan(“to multiply, abound, increase, extend, reward”), equivalent to many + -fold. Cognate with Middle High German manecvalten, Icelandic margfalda(“to multiply”), Swedish mångfaldiga(“to manifold, reproduce”).
etymonline
manifold (adj.)
"of many kinds; numerous in kind or variety; diverse; exhibiting or embracing many points, features, or characteristics," Old English monigfald (Anglian), manigfeald (West Saxon), "various, varied in appearance, complicated; many times magnified; numerous, abundant," from manig (see many) + -feald (see -fold). A Proto-Germanic compound, *managafalþaz (source also of Old Frisian manichfald, Middle Dutch menichvout, German mannigfalt, Swedish mångfalt, Gothic managfalþs), perhaps a loan-translation of Latin multiplex (see multiply).
It retains the original pronunciation of many. Old English also had a verbal form, manigfealdian "to multiply, abound, increase, extend;" in modern times the verb meant "to make multiple copies of by a single operation." Related: Manifoldness.
manifold (adv.)
"many times, in multiplied number or quantity," late Old English manigfealde, from manifold (adj.). Old English also had an adverb manigfealdlice "in various ways, manifoldly," from the source of manifold (adj.).
manifold (n.)
in mechanical sense, "pipe or chamber, usually of cast metal, with several outlets," by 1855, a shortening of manifold pipe (by 1845), which originally was used with reference to a type of musical instrument mentioned in the Old Testament. See manifold (adj.). As "pipe running from a carburetor to the cylinders in an internal combustion engine of an automobile," by 1904.
