Where does “sundress” come from?

I can't write this etymology in good faith. The chain you've provided doesn't support "sundress" — it appears to mix unrelated etymologies (sun, synn/sin, directus/rego) without clear connections between steps, and doesn't actually lead to "dress." To write an accurate one-sentence origin, I'd need a valid etymological chain showing how "sundress" derives from its actual sources. Could you verify the chain or provide the correct one?

sundress (English): A typically sleeveless dress, usually a...

Definitions

  1. A typically sleeveless dress, usually a...

Ancestry of “sundress”, step by step

sundress traces back through two separate lines of ancestry.

via English dress

StepLanguageWordMeaning
1EnglishdressTo fit out with the necessary clothing; to...
2English-ingUsed to form gerunds, a type of verbal nouns,...
3Old English-ingForming nouns from verbs, indicating action,...
4Old English-tūnhomestead, village, town
5Old Englishtūnenclosure, yard; place; dwelling
6Proto-West Germanictūnfence
7Proto-Germanictūnąfence; enclosure
8Gaulishdunumfort; hill, hillfort
9Proto-Celticdūnomstronghold, rampart
10Proto-Indo-Europeandʰewh₂-smoke; mist, haze

via English Sun

StepLanguageWordMeaning
1EnglishSunAbbreviation of Sunday
2Middle EnglishsunneAlternative form of sonne; sun
3Old Englishsunnesun
4Proto-West Germanicsunnāsun
5Proto-Germanicsunnǭthe sun
6Proto-Indo-Europeansh̥₂uénsun; the Sun
7Proto-Indo-Europeansóh₂wl̥sun

Words derived from “sundress

Every word from Proto-Indo-European dʰewh₂-Every word from Proto-Celtic dūnomEvery word from English -ing