Death and age are both subjective terms. Is age the number of years you have been alive or is it the stage of life you're in. Some people look behave and are genetically further along in life having beards and being done puberty at 14. And there is guys who dont hit it till they are 21. But does that make the first guy an adult? Does that make that second guy a Child?Immortal=Unable to die. Makes no sense that Doflamingo wants him dead if he's immortal.
Ageless=No longer ages.
And people can have their heart stop and not be dead. People can live without their brain if on the right life support. If they don't think or feel are they still alive?
The hormones in laws body should still progress him towards growth. Just not decay.
You should still be able to kill law. Law just can't die. Being killed and dieing aren't the same.