Is a human amputee still a biped?

Does the term “biped” or “quadruped” refer to the incidental characteristics of a creature, or the paradigmatic characteristics of that kind of creature?

Would a human amputee be a biped because humans in general are bipeds by nature?

Solution 1:

A biped (Oxford) is An animal that uses two legs for walking. Other dictionaries use almost identical wording. An animal (human or otherwise) that lacks legs can't use them, so isn't a biped.

That seems clear enough but actually it's more of a philosophical question than a semantic one. I'd could be tempted to agree with the dictionary and go on to say your hypothetical amputee is a member of a bipedal species, but not a biped themself. But what about someone who possesses legs but has lost the use of them? Or, to take it to an extreme, even someone who's metaphorically legless - i.e. has temporarily lost the use of their legs through drinking?* Or go the other way - someone born without lower limbs.

Humans are, after all, generally defined as bipeds, and I certainly wouldn't want to make the argument that physical disability (or even drunkenness) makes someone less human.

That, even if only on the grounds of inclusion, would suggest that the question's "paradigmatic characteristics" basis would be a good one to use. Even so, would we extend these inclusive arguments to creatures incapable of understanding them - an amputee ostrich for example, or an amputee robot (autonomous or otherwise)?

I'm afraid there is no clear answer; there may be a most suitable answer for a given situation, and I hope this answer has given you some information to make that choice.

*"No longer bipedal" would actually be a nice euphemism for falling down drunk.

Solution 2:

As "biped" is a scientific description of a particular clade, rather than an individual, all humans are bipeds, regardless of how many feet they actually have or use.

A human being who has lost a leg would best be described as "one-legged".