1.
If you describe something such as a desire or force as irresistible, you mean that it is so powerful that it makes you act in a certain way, and there is nothing you can do to prevent this.
It proved an irresistible temptation to Hall to go back.
= overwhelming
ADJ
• irresistibly
I found myself irresistibly drawn to Steve's world.
ADV: ADV with v
2.
If you describe something or someone as irresistible, you mean that they are so good or attractive that you cannot stop yourself from liking them or wanting them. (INFORMAL)
The music is irresistible.
ADJ
• irresistibly
She had a gamine charm which men found irresistibly attractive.
ADV: ADV adj