Parent and Nonparent is a false dichotomy. What do people respond when:
- all their children are grown and fully independent
- their only child was stillborn
- had a child but it died at a young age
- are currently fostering a child and hope to adopt them
- are currently fostering long-term but have no plans to adopt
- are currently fostering a child but expect to only provide respite (temporary care days to weeks)
- are not currently fostering but have fostered in the past and are still a registered foster parent
- have adopted a child but have no biological children
- have a living adopted child and a biological child that died at a young age
- are married to a person with biological children but have none of their own
- are living with a person with biological children but have none of their own
- are seriously dating (planning to move in/marry) a person with children
- does it matter if adopted/foster children are from a same-sex relationship?
- had a child with a previous spouse but currently have no custody
- had a child with a previous spouse but currently have supervised custody
- had a child with a previous spouse but currently have <50% joint custody
- have a disabled relative that they provide >50% support for
- have a disabled relative that lives with them but pays them rent
- have a disabled relative that pays rent but still needs additional support when medical bills pile up
Are you a parent? [ ]Yes [ ]No -- far too many edge cases
Have you ever impregnated a woman or been pregnant? -- too personal
Did you claim any dependents on your last tax return? -- probably the best you can do
After reading the comment: "haha yes I agree in a form this wouldn't work. the full context is that I am designing a system for organizing parts in a supply chain, for a physical product. There are a ton of people involved who do not need to understand technical jargon, so I was looking for the best term to categorize Parts that have subcomponents, and Parts that do not. Right now a request we see is "can I see all of the basic parts", but "basic" is too subjective. That's why we were looking for something like "nonparent" or "childless" parts to accurately reflect what is being asked for"
Since you are actually looking for a word to describe parts in a supply chain that have no child parts, a technical option would be "leaf". leaf parts are parts on the family tree that have no further branches. It comes from computer science data structures, but the idea is that leaves are the part of the branch that doesn't produce any further branches.