By Chinua Asuzu
Generally, a _recognizance _is a bond to the court or tribunal, whereby the recognizor undertakes to abide by some specified condition (for example, to appear for his trial, attend court when required, pay a debt, keep the peace, etc.)
More particularly, a recognizance is synonymous with a bail bond—it secures the return to court of a defendant in a criminal trial.
A reconnaissance, on the other hand, is a (law-enforcement, military, or security) intelligence-gathering examination, exercise, mission, or survey over (criminal, enemy, rival, or terrorist) activities, locations, or operations. The corresponding verb is reconnoiter.
Chinua Asuzu, Learned Writing (Partridge, 2019), 683.
