kiss o' kill

[waterballoon]

Does anyone have any suggestions for what kiss o' kill might mean?

It looks will o' wisp, which means "will of the wisp", so could it be that kiss o' kill means "kiss of the kill"? But that doesn't make too much sense does it.

So, I have a thought that the o' might stand for "or", so kiss o' kill in this context means "kiss (me) or (I'll) kill (you)"... Does that sound plausible? The song is after all, about a subject similar to a martyrdom.

Any suggestions?