CON - To study, especially in order to gain knowledge of.

NET - A mesh of string, cord or rope.

NOT - Negates the meaning of the modified verb.

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.

TEN - A numerical value equal to 10; the number occurring after nine and before eleven, represented in Roman numerals as X, in Arabic numerals as 10, and in the hexadecimal system (base 16) as A.

TOE - Each of the five digits on the end of the foot.

TON - A unit of weight (mass) equal to 2240 pounds (a long ton) or 2000 pounds (a short ton) or 1000 kilograms (a metric ton).

COT - A symbol of the trigonometric function cotangent.

TOT - A small child.

CENT - A coin having face value of one cent (in either of the above senses).

CONE - A surface of revolution formed by rotating a segment of a line around another line that intersects the first line.

NEON - The chemical element (symbol Ne) with an atomic number of 10.

NONE - Not any (one) of a given number or group of things. With singular or plural concord.

NOTE - Use; employment.

ONCE - One and only one time.

TENT - A pavilion or portable lodge consisting of skins, canvas, or some strong cloth, stretched and sustained by poles, used for sheltering persons from the weather.

TONE - A specific pitch.

TOTE - A bag, specifically a tote bag.

CONTENT - That which is contained.