epochal

As a noun milestone

is a stone milepost (or by extension in other materials), one of a series of numbered markers placed along a road at regular intervals, typically at the side of the road or in a median.

As a verb milestone

is to place milestones along (a road, etc).

As an adjective epochal is

of or pertaining to an epoch.

As adjectives the difference between modern and epochal

is that modern is pertaining to a current or recent time and style; not ancient while epochal is of or pertaining to an epoch.

As a noun modern

is someone who lives in modern times.

As adjectives the difference between epochal and epochmaking

is that epochal is of or pertaining to an epoch while epochmaking is bringing about an epoch; highly novel and influential.

As an adjective epochal

is of or pertaining to an epoch.

As a noun epocha is

archaic form of epoch.

As an adjective epochal

is of or pertaining to an epoch.

As a noun epochas is

plural of epocha.

As an adjective epochal

is of or pertaining to an epoch.

As an adverb epochally is

in an epochal manner.