is a specific kind of: hinder, impede.

is a broader term that covers: block off, blockade | barricade, barricado | barricade | asphyxiate, choke, stifle, suffocate | tie up | dam, dam up | block out, screen | earth up, land up | bar, barricade, block, block off, block up, blockade, stop | back up, choke, choke off, clog, clog up, congest, foul.

is the opposite of: disengage, free.

derivation: block, blocking | obstruction | blockage, closure, occlusion | impediment, impedimenta, obstructer, obstruction, obstructor | obturator | clogging, hindering, impeding, obstructive | occlusive.