Definition of "inauspicious"

And shake the yoke of inauspicious stars.

c. 1591–1595 (date written), William Shakespeare, “The Tragedie of Romeo and Ivliet”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act V, scene iii]

Inauspicious love.

1685, John Dryden, The Despairing Lover

It is not to be wondered at that a government instituted in times so inauspicious, should on experiment be found greatly deficient and inadequate to the purpose it was intended to answer.

1788, John Jay, as Publius, The Federalist, II

Class 745/1s suffered an inauspicious entry into traffic on the Stansted Express route on July 28, when the two units supplied (745103/106) both failed, as did a train sent to cover them (745108).

2020 August 12, “Network News: Triple failure of Class 745s on first day of Stansted services”, in Rail, page 17