inveterate

他是一个积习难改的烟民，从十几岁就开始抽烟。

He is an ___inveterate smoker who started smoking in his teens.

作为一个积习难改的赌徒，他已经输掉了三笔财富，却仍在追逐第四笔。

An ___inveterate gambler, he had lost three fortunes and was already chasing the fourth.

我的祖母是一个积习难改的贝壳收藏家，用她的收藏品填满了家里的每一个架子。

My grandmother was an ___inveterate collector of seashells, filling every shelf in the house with her finds.