I. ˈ ̷ ̷|fōld adjective
Etymology: Middle English fourfold, fourefold, from Old English fēowerfeald, from fēower four + -feald -fold
1. : having four parts or aspects : quadruple
2. : being four times as large, as great, or as many as some understood size, degree, or amount
a fourfold increase
3. : tetrad
II. adverb
Etymology: Middle English fourfold, fourefold, from fourfold, fourefold, adjective
: to four times as much or as many : by four times
increased fourfold