What does "reconnaissance" mean? In what circumstances could I use it?

Native speaker’s answer
Rebecca
A "reconnaissance" is a military search and observation. It can also mean a survey or research done before doing something! So the use is quite limited to context, I'd say. It's more common in reference to military searches, but you could also use it formally if you want to mention that you did research or a survey before doing something else. Ex: The commander called for a low-level reconnaissance to look for two soldiers on the mountain. Ex: We're conducting a quality reconnaissance on the product before launching it.