Easily offended or annoyed; quick to take offense or show irritation.
From 'huff' (an exclamation of annoyance or exasperation) plus the suffix '-y'. The word emerged in the 1600s describing someone prone to huffing and showing displeasure.
Huffy is a perfectly onomatopoetic word—it literally sounds like the huffing and puffing someone does when they're indignant, which is why children's books use it so effectively to describe grumpy characters.
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