定期保险单 meaning in English

period; period policy; term policy
term of policy
time policy

In a time policy there is no implied warranty that the ship shall be seaworthy at any stage of the adventure , but where , with the private of the assured , the ship is sent to sea in an unseaworthy state , the insurer is not liable for any loss attributable to unseaworthiness
在船舶定期保险单中，不存在船舶在海上冒险的任何阶段应当适航的默示保证，但若被保险人私谋，将处于不适航状态下的船舶派出海，保险人对可归因于不适航的任何损失不负责任。