[ad. late L. transforātiōn-em, f. transforāre: see prec.]
† 1. A seton; a thread or tape drawn through a fold of skin to maintain an issue. Obs.
1597. A. M., trans. Guillemeau’s Fr. Chirurg., cij b/1. The Needle for the Seton, or transforatione. Ibid., 39 b/2. All the which [cauteryes] haue but oue onlye apertion, or two, and is then called a transforatione or Seton.
2. The action of transforating, as in craniotomy.
1890. Billings, Med. Dict., Transforation,… repeated perforation of the base of the fœtal skull in craniotomy.
