رعب

مَرْعَبَةٌ ذ A frightful قَفْرَة [or desert destitute of herbage and of water ]. (K. [In the CK and TA, قَفْزَة is erroneously put for قَفْرَة.]) ― -b2- Also A person's springing, or leaping, [ towards another, ] and seating himself by the other's side, so as to cause the latter, not being aware, to be frightened. (K. [From its measure, it seems to be a simple subst., not an inf. n., signifying this action as being A cause of fear. ])