Umm...I'm not sure that it counts precisely for this thread but I think that being submissive means that you understand other people have at times the right to set boundaries for you that they know are in your best interests.
I think it is tricky, as Denu, has already stated very well, to say that someone is submissive because they do X or Y but rather they are submissive because they accept in the relationship the need to do X and Y and admit that it is for their own good.
I mean, for example, I live within some pretty strict boundaries when it comes to time keeping and alcohol which may on first glance look terrible and harsh (I thought so at the time too - which is why I had a few 'chats' with the cane) but I now realise that I should be accepting those boundaries as they've been put in place by people who care for me. I think over time, to be honest, I'm a nicer person because of those 'boundary fences' even if I do occasionally still 'kick the fences'.
But, and I know I'm not pushy, it seems to work for all of us and keep me on the 'straight and narrow'.