adjective

1. having many and various forms, features, parts, etc. manifold wisdom
2. of many sorts; many and varied; multifarious: used with a plural noun manifold duties
3. being such in many and various ways or for many reasons a manifold villain
4. comprising, consisting of, or operating several units or parts of one kind: said of certain devices

Etymology: ME < OE manigfeald: see many & -fold

noun

1. something that is manifold
2. a pipe with one inlet and several outlets or with one outlet and several inlets, for connecting with other pipes, as, in an automobile, for conducting exhausts from each cylinder into a single exhaust pipe

transitive verb

1. to make manifold; multiply
2. to make more than one copy of to manifold a letter with carbon paper