frus‧trat‧ing /frʌˈstreɪtɪŋ $ ˈfrʌstreɪtɪŋ/
adjective making you feel annoyed, upset, or impatient because you cannot do what you want to do:
My job can be very frustrating sometimes. This is an immensely frustrating experience for the student. [TahlilGaran] Dictionary of Contemporary English ▲