hydra /ˈhaɪdrə/ noun
plural hydras
plural hydras
Learner's definition of HYDRA
1
Hydra [singular] : a monster in Greek mythology that has many heads(希腊神话中的)多头蛇,许德拉
2
[count] : a very complicated and serious problem that cannot be easily solved棘手复杂的问题;难以根绝的祸患