Where does “thouten” come from?

thouten (Middle English) comes from Middle English þou, from Old English þū, from Proto-West Germanic þū, from Proto-Germanic *þū, from Proto-Indo-European túh₂ — you, thou.

thouten (Middle English): To address someone with "thou", i.e. with familiarity or informality

Definitions

To address someone with "thou", i.e. with familiarity or informality

Ancestry of “thouten”, step by step

Step	Language	Word	Meaning
1	Middle English	þou	thou second-person singular pronoun; you
2	Old English	þū	you, thou (nominative singular)
3	Proto-West Germanic	þū	you
4	Proto-Germanic	*þū	—
5	Proto-Indo-European	túh₂	you, thou

Every word from Proto-Indo-European túh₂ →Every word from Proto-Germanic *þū →Every word from Proto-West Germanic þū →