to turn edge: (of a sharp instrument) to have the edge bent so as to make it useless for cutting, to become blunt. Also figurative. Cf. sense 8c(a)…

intransitive. Of the edge of a weapon or implement: to bend back so as to become blunted; = main sense 8c(b). Obsolete.

intransitive. To grow blunt. Frequently figurative and in figurative context. Obsolete.

intransitive. Of the edge or blade of a sharp instrument: to assume a curved form, to bend; to become blunted by bending. Cf. earlier to turn again…

intransitive. To become dull of edge or point.