to suddenly buy as much food, fuel, etc. as you can because you are worried about something bad that may happen and that may mean that there is not enough food, etc. available

The situation in the city was tense and residents withdrew cash and began panic buying. 市内局势紧张，居民纷纷提取现金，开始恐慌性抢购。

The prime minister urged consumers not to panic buy fuel ahead of any action. 总理敦促消费者在采取任何行动之前不要恐慌性购买燃料。

something bought suddenly, especially because you are worried about something bad that may happen and that may mean that there is not enough food, etc. available

Major supermarkets enforced new rules to stop panic buys. 大型超市实施了新的规则来阻止恐慌性购买。

I will not be rushed into making a panic buy. 我不会受诱惑急着去参与恐慌性购买的。