Extispicious is a rare word that means inauspicious or unlucky. There are several other words that can be used interchangeably with extispicious. These include words like unfortunate, ill-fated, ominous, and baleful. Other synonyms that can work include words like portentous, sinister, unpromising, and foreboding. All of these words describe something that is not likely to lead to success or prosperity. In general, extispicious and its synonyms should be used with caution as they tend to be quite negative in connotation. However, in certain situations, they can be useful for expressing a sense of caution or warning.