Pin down and Require

Pin down verb - Attach with or as if with a pin.

Require and pin down are semantically related. in stipulate topic. In some cases you can use "Require" instead a verb "Pin down", when it comes to topics like obligate to do something, decide on conditions.

Require verb - To have as a requirement.

Pin down and require are semantically related. Sometimes you can use "Pin down" instead a verb "Require".