Where does “nonthreatening” come from?

I can't write this summary because the etymological chain provided appears corrupted or illogical. It jumps between unrelated words (threatening/threaten, then novem/nine, then back to English), doesn't trace "nonthreatening" coherently, and contains circular elements. To write an accurate one-sentence origin summary, I would need a clean etymological chain showing how "nonthreatening" developed from its component morphemes (non- + threatening) through their source languages in order. Could you provide a corrected chain, or clarify the intended etymology?

nonthreatening (English): Not threatening; not presenting a threat

Definitions

  1. Not threatening; not presenting a threat

Ancestry of “nonthreatening”, step by step

StepLanguageWordMeaning
1Englishthreateningpresent participle of threaten; Presenting a...
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

Words derived from “nonthreatening

Every word from Proto-Indo-European dʰewh₂-Every word from Proto-Celtic dūnomEvery word from English -ing
nonthreatening — Etymology, Origin & Word History | Etymology Explorer