出典:Wiktionary
From Middle English therto, from 古期英語 þǣrtō (“thereto”), equivalent to there + to. Cognate with Scots tharto, thereto (“thereto”), Saterland Frisian deertou (“thereto”), West Frisian dêrta (“thereto”), Dutch daartoe (“thereto; for that”), German Low German daarto (“to that; for that; thereto”), German dazu (“to that; for that; thereto”).
thereto (not comparable)