Reaching into your hat to pull out a rabbit and instead removing a sock can seem like an inauspicious start to your magic show. Inauspicious describes something that seems unpromising or unlikely to be successful.
If it's unlucky, badly timed, or it seems to point to an unhappy outcome, it's inauspicious. A dark, stormy sky on the day of a wedding can be seen as inauspicious, and so can an awkward job interview. The opposite of inauspicious is auspicious, which means lucky or promising. Both words come from the Latin auspicium, which has to do with predicting the future by observing the flight of birds.