1. most easily annoyed or irritated; most bad-tempered
Usage: superlative form of testy

Examples

• He becomes the testiest when he’s hungry.
• Of all the customers today, she was the testiest one.
• The testiest member of the committee always objects to new proposals.
• My grandfather is at his testiest in the morning before his coffee.
• The testiest responses came from people who had been waiting the longest.
• She’s the testiest driver I know, honking at every minor delay.