1. 许可；批准
    If you give someone or something the go-ahead, you give them permission to start doing something.

    e.g. The Greek government today gave the go-ahead for five major road schemes...
           希腊政府今天批准了5项重大的道路修建方案。
    e.g. Don''t do any major repair work until you get the go-ahead from your insurers.
           除非经保险公司同意，否则不要进行任何大修。

2. 有进取心的；具有开拓精神的
    A go-ahead person or organization tries hard to succeed, often by using new methods.

    e.g. Fairview Estate is one of the oldest and the most go-ahead wine producers in South Africa.
           “丽景庄园”是南非历史最悠久、最具创新精神的酿酒商之一。

1. readiness to embark on bold new ventures

    Synonym: enterpriseenterprisingnessinitiative

2. a signal to proceed

    Synonym: green light