Boring, insipid, or dreary; lacking interest or flavor; tiresome.
パーティーは人が少なくてあじけなかった。
The party was dull because there were few people.
味付けが薄くて、料理があじけない。
The seasoning is weak and the dish tastes insipid.
彼の話し方はいつもあじけなく感じる。
I always find his way of speaking rather dull.