The difference between Average and Usual

When used as adjectives, average means constituting or relating to the average, whereas usual means most commonly occurring.

Average is also noun with the meaning: the arithmetic mean.

Average is also verb with the meaning: to compute the average of, especially the arithmetic mean.

check bellow for the other definitions of Average and Usual

Average as a noun (mathematics):

The arithmetic mean.

Examples:

"The average of 10, 20 and 24 is (10 + 20 + 24)/3 = 18."
Average as a noun (statistics):

Any measure of central tendency, especially any mean, the median, or the mode.
Average as a noun (legal, marine):

Financial loss due to damage to transported goods; compensation for damage or loss.
Average as a noun:

Customs duty or similar charge payable on transported goods.
Average as a noun:

Proportional or equitable distribution of financial expense.
Average as a noun (sports):

An indication of a player's ability calculated from his scoring record, etc.

Examples:

"batting average'"
Average as a noun (UK, in the plural):

In the corn trade, the medial price of the several kinds of grain in the principal corn markets.

Average as an adjective (not comparable):

Constituting or relating to the average.

Examples:

"The average age of the participants was 18.5."
Average as an adjective:

Neither very good nor very bad; rated somewhere in the middle of all others in the same category.

Examples:

"I soon found I was only an average chess player."
Average as an adjective:

Typical.

Examples:

"The average family will not need the more expensive features of this product."
Average as an adjective (informal):

Not outstanding, not good, banal; bad or poor.

Average as a verb (transitive):

To compute the average of, especially the arithmetic mean.

Examples:

"If you average 10, 20 and 24, you get 18."
Average as a verb (transitive):

Over a period of time or across members of a population, to have or generate a mean value of.

Examples:

"The daily high temperature last month averaged 15°C."

"I averaged 75% in my examinations this year."
Average as a verb (transitive):

To divide among a number, according to a given proportion.

Examples:

"to average a loss"
Average as a verb (intransitive):

To be, generally or on average.

Average as a noun (UK, legal, obsolete):

The service that a tenant owed his lord, to be done by the animals of the tenant, such as the transportation of wheat, turf, etc.

Usual as an adjective:

Most commonly occurring; typical.

Examples:

"The preference of a boy to a girl is a usual occurrence in some parts of China."

"It is becoming more usual these days to rear children as bilingual."