say it: ree-KAH-nuh-suhns
reconnaissance is a noun meaning "the act of reconnoitring (especially to gain information about an enemy or potential enemy)". It is pronounced /ɹiˈkɑnəsəns/ — ree-KAH-nuh-suhns. It carries one recorded sense.
the act of reconnoitring (especially to gain information about an enemy or potential enemy)
“an exchange of fire occurred on a reconnaissance mission”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for reconnaissance come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.