Waspish describes more than being upset; it implies a sharp, bitter type of annoyance or irritation. His waspish remark made it clear he was really frustrated with the delay.
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Facial Expression
When describing a person's expression as waspish, it suggests a visibly annoyed, displeased, or snappy demeanor. Her waspish frown showed everyone to stay away.
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Not Always Direct
Waspish behavior can be indirect, not confronting someone openly but with clear undertones of annoyance. His waspish tone hinted he was unhappy, although he didn't say it outright.