slow: [OE] The etymological notion underlying slow is ‘dullness, sluggishness’; ‘lack of speed’ is a secondary development. The word goes back to a prehistoric Germanic *slæwaz, which also produced Swedish slö and Danish sløv ‘dull, blunt’. The original idea of ‘sluggishness’ is better preserved in the derivative sloth [12] (etymologically ‘slow-ness’). => sloth[slow etymology, slow origin, 英语词源]