threefold

• three-fold, 3-fold

From Middle English threfold, from Old English þrīfeald. Equivalent to three +‎ -fold.

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threefold (not comparable)

1. Three times as great.
   • 2020 May 20, Andrew Haines talks to Stefanie Foster, “Repurpose rail for the 2020s”, in Rail, page 33:

     "We recognise that electrifying more of the railway is likely to be necessary to deliver decarbonisation," it stated.
     There's clearly a growing momentum in that direction, but some significant hurdles have still to be overcome - not least the legacy of the three-fold increase in cost on the Great Western Electrification Programme, which has become the poster project for expensive wiring.

2. Triple. (clarification of this definition is needed)

• (three times as great): thrissome; see also Thesaurus:threefold
• (triple): ternary, trine; see also Thesaurus:triple

threefold (not comparable)

1. By a factor of three.

• thrice, trebly; see also Thesaurus:thrice

threefold (plural threefolds)

1. (mathematics) An algebraic variety of dimension 3.
   • 2015, Xun Yu, “McKay correspondence and new Calabi-Yau threefolds”, in (Please provide the book title or journal name)‎^[1]:

     In this way, we find some new pairs ${\displaystyle (h^{1,1},\;h^{2,1})}$ of Hodge numbers of Calabi-Yau threefolds.

threefold (third-person singular simple present threefolds, present participle threefolding, simple past and past participle threefolded)

1. (transitive) To make threefold; to triple.