extremely interested in something, to a degree that some people find unreasonable

His dedication to fitness was almost fanatical. 他对健身的热情几乎到了入迷的地步。

Gary's fanatical about football. 加里对足球很痴迷。

holding extreme beliefs that may lead to unreasonable or violent behaviour

a fanatical group that has threatened to assassinate doctors 一个威胁要暗杀医生的极端组织