I suspect MeteorMarc meant 'euthanasia' in the philosophy sense of a death that is (a1) rationally planned over a period of time and (b1) in the dying persons overall interest. Which can be contrasted with 'suicide' in a sense commonly used in suicide prevention care and research, where the act (a2) often results from temporary cognitive or emotional instability and (b2) is seldom in the dying persons overall interest. You on the other hand perhaps meant to distinguish between the dying person (a) getting assistance vs in dying (b) acting alone.
A third termological option is 'assisted dying'. A big complication is that 'euthanasia' comes with quite different historical baggage in different countries.