COP - To (be forced to) take; to receive; to shoulder; to bear, especially blame or punishment for a particular instance of wrongdoing.
POT - A vessel used for cooking or storing food.
PRO - An advantage of something, especially when contrasted with its disadvantages (cons).
ROT - To suffer decomposition due to biological action, especially by fungi or bacteria.
TOO - Likewise.
TOP - That part of an object furthest away in the opposite direction from that in which an unsupported object would fall.
COO - The murmuring sound made by a dove or pigeon.
COT - A symbol of the trigonometric function cotangent.
OPT - To choose; to select.
COOP - A pen or enclosure for birds.
CROP - A plant, especially a cereal, grown to be harvested as food, livestock fodder, or fuel or for any other economic purpose.
POOR - With little or no possessions or money.
PORT - A place on the coast at which ships can shelter, or dock to load and unload cargo or passengers.
ROOT - The part of a plant, generally underground, that absorbs water and nutrients.
COOT - Any of various aquatic birds of the genus Fulica that are mainly black with a prominent frontal shield on the forehead.
ROTOR - A rotating part of a mechanical device, for example in an electric motor, generator, alternator or pump.
TROOP - A collection of people; a company; a number; a multitude.
COOPT - To commandeer, appropriate or take over.
PROCTOR - A person who supervises students as they take an examination, in the United States at the college/university level; often the department secretary, or a fellow/graduate student.