encumberment; encumbrance

(quantum field theory) One of a set of three spacelike (and possibly also one timelike) four-dimensional vectors which are orthonormal within some inertial reference frame.

(engineering, archaic) A device for saving power in stopping and starting a railroad car, by means of a heavy flywheel.

Relating to a phobia. / Experiencing or expressing phobia (strong fear and/or dislike).