Percentage
Part of speech: noun
Definition: The amount, number or rate of something, regarded as part of a total of 100; a part of a whole. A share of the profits. Benefit or advantage.
Example sentence: Percentage margins don't matter. What matters always is dollar margins: the actual dollar amount. Companies are valued not on their percentage margins, but on how many dollars they actually make, and a multiple of that.
Average
Part of speech: noun
Definition: The arithmetic mean.Any measure of central tendency, especially any mean, the median, or the mode (see Usage notes below).An indication of a player's ability calculated from his scoring record, etc.
Part of speech: adjective
Definition: Constituting or relating to the average.Neither very good nor very bad; rated somewhere in the middle of all others in the same category.Typical.Bad or undesirable.
Part of speech: verb
Definition: To compute the arithmetic mean of.Over a period of time or across members of a population, to have or generate a mean value of.