What is the origin of auspicate?
Romans were addicted to religion, law, and the military (not always sharply differentiated), and no public business could be conducted without first taking the auspices. The basic Latin word is auspex (stem auspic-), literally “bird watcher.” The syllable au- is a reduced form of avi-, the stem of the Latin noun avis “bird”; the suffix -spex means “one who watches or inspects,” a derivative of the verb specere “to observe, watch” (which has many derivatives in English, e.g., expect, inspect, suspect, etc.). The Latin derivative noun auspicium “bird watching” also applied to other forms of divination, e.g., ex caelō, i.e., observing thunder and lightning; ex quadrupedibus, observing the behavior of four-footed animals, e.g. a wolf eating grass; ex dīrīs from observing dreadful, uncanny, or dire signs. There were other forms of auspices too silly to mention, but when the results of public elections were at stake or there was an important, controversial bill being debated in the Senate, why surely the gods had to approve (or not). Auspicate comes from the Latin past participle auspicātus, a derivative of the verb auspicārī “to take the auspices.” Auspicate entered English in the early 17th century.