thir·ty·fold I. \| ̷ ̷ ̷ ̷|fōld\adjective Etymology: Middle English thrittifold, from Old English thrītigfeald, from thrītig thirty + -feald -fold 1.: having 30 parts or aspects 2.: being 30 times as large, as great, or as many as some understood size, degree, or amount < a thirtyfold increase > II. adverb : to 30 times as much or as many : by 30 times < brought forth fruit, some an hundredfold, some sixtyfold, some thirtyfold — Mt 13:8 (Authorized Version) >