Minimums is the lowest altitude a pilot can descend to on an instrument approach for landing as well as the minimum reported visibility required on the ground in order to begin the approach. Minimums will vary with the type of approach, terrain and obstacles (buildings, towers etc) in the immediate airport area.

Why do planes say minimum?

In order to ensure that the pilot can safely transition from instrument flying to a visual landing, the FAA establishes minimums for every type of approach to every runway to every major airport. As an example, the minimums for one particular approach might be 200 feet and ½ mile.

What minimums mean?

1 : the least quantity assignable, admissible, or possible. 2 : the lowest degree or amount of variation (as of temperature) reached or recorded. minimum.