copper-bottomed

adj (esp Brit) safe in every way; certain not to fail 绝对安全的; 万无一失的: a copper-bottomed guarantee, assurance, deal, etc 可靠的保证、 绝对的把握、 毫无风险的交易.

coordination, coordinator, coorperation, coot, cop, cop-out, copain, copartner, copartnership, cope, cope with, copeck (also kopeck), Copernican, copier, coping, coping-stone, copious, copiously, copper, copper beech, copperhead, copperplate, coppice, copra, copse, Copt, Coptic, copula, copulate, copulation, copulative, copy, copy desk, copy-book, copy-cat, copy-typist, copy-writer, copyist, copyright, coquetry,