pet·ri·fy / ˈpetrəˌfī/ • v. (-fies, -fied) [tr.] 1. make (someone) so frightened that they are unable to move or think: his icy controlled quietness petrified her| [as adj.] (petrified) the petrified child clung to her mother. 2. change (organic matter) into a stony concretion by encrusting or replacing its original substance with a calcareous, siliceous, or other mineral deposit. ∎ [intr.] (of organic matter) become converted into stone or a stony substance in such a way. ∎ fig. deprive or become deprived of vitality or the capacity for change: [tr.] death merely petrifies things for those who go on living | [intr.] the inner life of the communist parties petrified.