definition of
four-fold

[1] #1 four-fold s. [quadruple, quadruplicate, quadruplex, fourfold] having four units or components; "quadruple rhythm has four beats per measure"; "quadruplex wire". wn

[2] #2 four-fold s. [quadruple, fourfold] four times as great or many; "a fourfold increase in the dosage". wn