The difference between Common and Rare

When used as verbs, common means to communicate (something), whereas rare means to rear, rise up, start backwards.

When used as adjectives, common means mutual, whereas rare means very uncommon.

Common is also noun with the meaning: mutual good, shared by more than one.

check bellow for the other definitions of Common and Rare

Common as an adjective:

Mutual; shared by more than one.

Examples:

"The two competitors have the common aim of winning the championship."

"Winning the championship is an aim common to the two competitors."
Common as an adjective:

Occurring or happening regularly or frequently; usual.

Examples:

"It is common to find sharks off this coast."
Common as an adjective:

Found in large numbers or in a large quantity.

Examples:

"Sharks are common in these waters."
Common as an adjective:

Simple, ordinary or vulgar.
Common as an adjective (grammar):

In some languages, particularly Germanic languages, of the gender originating from the coalescence of the masculine and feminine categories of nouns.
Common as an adjective (grammar):

Of or pertaining to common nouns as opposed to proper nouns.
Common as an adjective:

Vernacular, referring to the name of a kind of plant or animal, i.e., common name vs. scientific name.
Common as an adjective (obsolete):

Profane; polluted.
Common as an adjective (obsolete):

Given to lewd habits; prostitute.

Common as a noun:

Mutual good, shared by more than one.
Common as a noun:

A tract of land in common ownership; common land.
Common as a noun:

The people; the community.
Common as a noun (legal):

The right of taking a profit in the land of another, in common either with the owner or with other persons; so called from the community of interest which arises between the claimant of the right and the owner of the soil, or between the claimants and other commoners entitled to the same right.

Common as a verb (obsolete):

To communicate (something).
Common as a verb (obsolete):

To converse, talk.
Common as a verb (obsolete):

To have sex.
Common as a verb (obsolete):

To participate.

Examples:

"rfquotek Sir Thomas More"
Common as a verb (obsolete):

To have a joint right with others in common ground.

Examples:

"rfquotek Johnson"
Common as a verb (obsolete):

To board together; to eat at a table in common.

Rare as an adjective:

Very uncommon; scarce.

Examples:

"Black pearls are very rare and therefore very valuable."

"synonyms: scarce selcouth seld seldsome selly geason uncommon"

"ant common frequent"
Rare as an adjective (of a gas):

Thin; of low density.

Rare as an adjective (cooking, particularly meats):

Cooked very lightly, so the meat is still red (in the case of steak or beef in the general sense).

Examples:

"ant well done"

Rare as a verb (US, intransitive):

To rear, rise up, start backwards.
Rare as a verb (US, transitive):

To rear, bring up, raise.