pentennial

As adjectives the difference between centennial and pentennial

is that centennial is relating to, or associated with, the commemoration of an event that happened a hundred years before while pentennial is (label) that occurs every five years.

As a noun centennial

is the hundredth anniversary of an event or happening.

As a noun year

is the time it takes the earth to complete one revolution of the sun (between 36524 and 36526 days depending on the point of reference).

As an adjective pentennial is

(label) that occurs every five years.

As a numeral five

is (cardinal) a numerical value equal to ; the number following four and preceding six this many dots (•••••).

As a noun five

is the digit/figure 5.

As an adjective pentennial is

(label) that occurs every five years.