CON - To study, especially in order to gain knowledge of.
COP - To (be forced to) take; to receive; to shoulder; to bear, especially blame or punishment for a particular instance of wrongdoing.
CUE - An action or event that is a signal for somebody to do something.
CUP - A concave vessel for drinking from, usually made of opaque material (as opposed to a glass).
ONE - A numerical value equal to 1; the first number in the set of natural numbers (especially in number theory); the cardinality of the smallest nonempty set. Ordinal: first.
PEN - An enclosed area used to contain domesticated animals, especially sheep or cattle.
PUN - To beat; strike with force; ram; pound, as in a mortar; reduce to powder.
CONE - A surface of revolution formed by rotating a segment of a line around another line that intersects the first line.
COPE - To deal effectively with something difficult.
NOPE - To hit someone on the head.
ONCE - One and only one time.
OPEN - Which is not closed; accessible; unimpeded; as, an open gate.
UPON - Being above and in contact with another.
COUP - A quick, brilliant, and highly successful act; a triumph.
PEON - A lowly person, a peasant or serf, a labourer who is obliged to do menial work.
OUNCE - An avoirdupois ounce, weighing 1/16 of an avoirdupois pound, or 28.3495 grams.
COUPE - An ice cream dessert; the glass it is served in.
POUNCE - A type of fine powder sprinkled over wet ink to dry the ink after writing.