You must have misunderstood something. Your question makes no sense because there is no definite article or relative pronouin that begins with "wo-" or is the part after "wo-" in an existing wo-word.
D definite article is a word that accompanies a noun, indicates it's grammatical gender (at least in languages where nouns have genders) and marks the nous as being not just any thing but exactly this thing. (It indicates the nouns definiteness.)
German has exactly 6 definite articles:
- der (the)
Der Mann schläft. The man is sleeping.
- die (the)
Die Frau schläft. The woman is sleeping.
- das (the)
Das Kind schläft. The child is sleeping.
- des (the)
Das Kleid des Kindes ist rot. The dress of the child is red.
- dem (the)
Das Kleid gehört dem Kind. The dress belongs to *the child.
- den (the)
Das Kind sieht den Mann. The child sees the man.
There are no other words in German that are definite articles. None of these words begins with "wo-". So, non of them is a wo-word. Also none of these 6 words is the part after "wo-" of any existing wo-word.
A relative pronoun is a word that initiates a relative clause.
German has exactly 20 relative pronouns. You can arrange them in 3 groups:
Der Mann, der dort saß, lächelte. - The man who sat there smiled.
Die Frau, die dort saß, lächelte. - The woman who sat there smiled.
Das Kind, das dort saß, lächelte. - The child who sat there smiled.
Der Mann, dem ich zuhörte, lächelte. - The man who who I was listening to smiled.
Der Mann, den ich sah, lächelte. - The man who who saw smiled.
Die Männer, denen ich zuhörte, lächelten. - The men who who I was listening to smiled.
Die Frau, deren Hund bellte, lächelte. - The woman whose dog was barking smiled.
Der Mann, dessen Hund bellte, lächelte. - The woman whose dog was barking smiled.
- derer (rare)
Er hatte einige Zaubersprüche, derer er sich nicht mehr ganz entsinnen konnte. - He had some spells that he couldn't quite remember.
Der Mann, welcher dort saß, lächelte. - The man who sat there smiled.
Die Frau, welche dort saß, lächelte. - The woman who sat there smiled.
Das Kind, welches dort saß, lächelte. - The child who sat there smiled.
Der Mann, welchem ich zuhörte, lächelte. - The man who who I was listening to smiled.
Der Mann, welchen ich sah, lächelte. - The man who who saw smiled.
- wer (animate: humans, animals, androids, etc.)
Wer will, kann gehen. - Whoever wants to can go.
- was (inanimate: anything else but humans animals etc.)
Ich mache, was ich will. - I do what I want.
- wessen (animate)
Wessen Brot ich esse, dessen Lied singe ich. - Whose bread I eat, whose song I sing.
- wes (old fashioned, animate)
Wes Brot ich ess', des Lied ich sing'. - Whose bread I eat, whose song I sing.
- wen (animate)
Wen man auch fragt, alle sagen dasselbe. - Whoever you ask, they all say the same thing.
- wem (animate)
Ich sage das, wem ich will. - I'll say this to whomever I want.
This list of relative pronouns is complete. No other German word is a relative pronoun. And again: None of them starts with "wo-" or ist the part after "wo-" in a wo-word.
There is no category named wo-word or Wo-Wort in German grammar. (I had to google for this term when I read this question.) I found these 16 word that match the definition given in the article linked in the question:
wobei, wodurch, woher, wohin, womit, wonach, woran, worauf, woraus, worein, worin, worum, worüber, wovon, wovor, wozu
All these words are adverbs. (Some of them are pronominal adverbs, some can be used as interrogative adverbs, but they are all adverbs.) There are many more adverbs, most of them do not start with "wo-": hier, draußen, bergauf, heute, darum, deshalb, ...
There is nothing special about adverbs that start with "wo-" (at least not more special than verbs starting with "ab-" or any other prefix) and there is no relation between these adverbs and any articles or pronouns.