Meaning of DIRECTIONAL in English

di ‧ rec ‧ tion ‧ al /dəˈrekʃ ə nəl, dɪˈrekʃ ə nəl, daɪ-/ BrE AmE adjective technical

1 . relating to the direction in which something is pointing or moving

2 . a directional piece of equipment receives or gives out radio signals from some directions more strongly than others

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.