"fourfold" in the adjective sense

1. quadruple, fourfold, four-fold

four times as great or many

"a fourfold increase in the dosage"

2. quadruple, quadruplicate, quadruplex, fourfold, four-fold

having four units or components

"quadruple rhythm has four beats per measure"

"quadruplex wire"

"fourfold" in the adverb sense

1. fourfold, four times

by a factor of four

"the price of gasoline has increased fourfold over the past two years"

Source: WordNet® (An amazing lexical database of English)

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