What is the origin of reconnoiter?

Reconnoiter “to inspect to gain information for military purposes” is an adaptation of obsolete French reconnoître “to explore” (compare modern French reconnaître “to recognize”). Reconnoître derives from Latin re- “again” and cognōscere “to know,” and as we learned from the recent Word of the Day gnomon, the gni-/gno- element, meaning “knowledge,” is found in numerous Latin-derived terms, from cognitive and recognize to incognito and ignorant. Reconnoître became reconnaître in modern French because of a spelling reform; by the early 1800s, the digraph oi had developed two different pronunciations—“eh” and “wah”—that caused ambiguity in writing. To rectify this shift, the 1835 edition of the Académie française’s dictionary of the French language changed the spelling of all words that contained the oi pronounced as “eh” from oi to ai. This also explains why the word connoisseur, which was borrowed into English a century before this spelling reform, retains the original French spelling while its modern French counterpart, connaisseur, reflects the reformed spelling. Reconnoiter was first recorded in English in the first decade of the 18th century.