What is the most "useless" organ in the human body, besides the appendix?
Not sure about organs but they're several body parts that are useless are, Wisdom teeth which are a pain to be removed anyway, Tonsils which are also a pain to be removed, Tail Bones which for some reason are sometimes broken, and for men nipples, they dont feed babies like we do or can do.
I'd argue that while there are organs that are less necessary for life, no organ is ever "useless".
Let's first talk about what an organ is - which is a group of millions of cells which work together to perform a certain function. While there is debate over how many organs humans have (because of the loose definition, some people will call something an organ while others won't), a reasonable number is 78.
And so now we come to the question - of these 78 organs, which is the most useless, besides the appendix. To which is the reply - the appendix isn't useless.
The appendix, for a very long time, was treated as a useless organ by the medical community. I remember growing up in the 1970s and 1980s and hearing that the only thing the appendix was good for was getting infected. I remember hearing one or two suggestions that the appendix, if anyone should happen to be doing surgery in the area, should just go ahead and remove it. The justification was that the appendix was a holdover, a vestigial structure, from our ancient ancestors. However, it is now known that the appendix holds copies of gut microorganisms so that when the colon flushes itself (i.e. diarrhea), it's the appendix that sends out new microorganisms.
But are there organs which are "useless"?
There are certainly organs which are not necessary for the maintenance of life - in fact, there are plenty of those. Take the gall bladder, for instance - it holds bile for use in digestion. If the gall bladder is removed, the liver drips out bile over the course of the day. And so digestion changes (and dietary changes are needed to keep someone who has had their gall bladder removed more comfortable) - it isn't necessary for life, but it helps make digestion more comfortable.
And so I'd argue that while there are organs that are less necessary for life, no organ is ever "useless".