Extra Definition

Augury, which means 'the art or practice of divination from signs or omens', and hence 'an omen, token, or indication', is a Latin derivative. The immediate source is Latin augurium, which is derived from a Latin base form augur.

In ancient Rome, the augures were official diviners, and were one of the four main groups of priests. Though they used various methods of divination, an augur would often use the flight or behavior of birds as a primary method. (Compare a haruspex, an originally Etruscan diviner who divined by examining the entrails of slaughtered animals. I personally find tea-leaves a much neater procedure.)

In English, augur is normally used as a noun meaning 'a soothsayer; prophet' or as a verb meaning 'to divine or predict' and also 'to serve as an omen of; foreshadow'. The historical use meaning 'a Roman augur' is comparatively rare.

The ultimate origin of Latin augur is uncertain. It was once considered to be derived from avi and ger(o), meaning 'directing the birds', but this is now usually considered a folk etymology. The
probable origin is from Latin augere 'to increase' (the source of English augment, among others), alluding to the growth or prosperity that successful divination would enable.