No, Lyell, you don't understand me correctly.
Each of those words can fit the puzzle because they both start with du, and that may be all that's needed for them to fit. That is, the last three letters do not intersect with anything else.
I ask this question because there are specific puzzles that reply on this multiple, similarly spelled answer scenario as the basis of their appeal. There is one in a local paper every week. People pay to make entries and the trick is to come closest to solving the puzzle with the most correct answers.
This type of puzzle must have a name.
If I have a name then I can find some software to help me generate them.