1. Foretoken（前兆） -- 词源：古英语"fore-"（前）+ "tacn"（标记） -- 特点：中性词，强调客观存在的先行迹象 -- 搭配：常接自然现象（a foretoken of storm） -- 例：The sudden drop in barometric pressure was a foretoken of the approaching typhoon.
2. Presage（预兆/预示） -- 词源：拉丁语"praesagium"（先知） -- 特点：强调主观预感的征兆，多用于文学语境 -- 搭配：presage disaster/success -- 例：The owl’s cry at midnight was believed to presage death in medieval folklore.
3. Prognostic（预后征兆） -- 词源：希腊语"pro-"（前）+ "gnōstikos"（知晓） -- 特点：医学/技术用语，指可量化的预测指标 -- 搭配：clinical prognostics -- 例：Elevated white blood cell count is a prognostic of infection.
4. Omen（兆头） -- 词源：拉丁语"ōmen"（神谕） -- 特点：强烈迷信色彩，特指超自然征兆 -- 搭配：good/bad omen -- 例：Ancient Romans considered thunder on the wedding day as an ill omen.
5. Augury（占卜预兆） -- 词源：拉丁语"augurium"（鸟占） -- 特点：专指通过占卜仪式获得的征兆 -- 搭配：practice augury -- 例：The flight patterns of birds were studied for augury in Etruscan religion.
6. Portent（凶兆） -- 词源：拉丁语"portendere"（预示） -- 特点：强调重大不祥之兆，戏剧性强 -- 搭配：portent of doom -- 例：The solar eclipse was viewed as a portent of the emperor’s downfall.
An occurrence supposed to portend, or show the character of, some future event; any indication or action regarded as a foreshowing; a foreboding; a presage; an augury.
To divine or to foreshow by signs or portents; to have omens or premonitions regarding; to predict; to augur; as, to omen ill of an enterprise.
That which portends, or foretoken; esp., that which portends evil; a sign of coming calamity; an omen; a sign.
An occurrence supposed to portend, or show the character of, some future event; any indication or action regarded as a foreshowing; a foreboding; a presage; an augury.
To divine or to foreshow by signs or portents; to have omens or premonitions regarding; to predict; to augur; as, to omen ill of an enterprise.
That which portends, or foretoken; esp., that which portends evil; a sign of coming calamity; an omen; a sign.
