DuckCorp Dico

Found one definition

1.                 From English-日本語 (にほんご) FreeDict+WikDict dictionary ver. 2022.11.18:
                   
   
   
                   
                     
   dull //dəl// //dəɫ// //dʌl// <adj>
   1. つまらない, 退屈
   boring, not exciting or interesting
   2. 鈍い 2.
   lacking the ability to cut easily; not sharp
    3.
   not bright or intelligent