I assume you are referring to the use of the term in relationship to goals and projects and not the original description of a stone marking off miles on a road. While it is not actually an antonym for a milestone, the opposite could be considered to be "setback".
Nadir
The plural of milestone is milestones. As in "the milestones mark the approximate distance".
Antonym for permanent: Temporary Antonym for abundant: Scarce
yes clever is antonym and it's antonym is stupid, fool
what is the antonym for full
Nadir
Meeting at the Milestone was created in 1947.
Milestone S.r.l. was created in 1996.
Milestone Records was created in 1966.
Milestone Media was created in 1993.
Milestone Media ended in 1996.
Zero Milestone was created in 1923.
Milestone Systems was created in 1998.
Milestone Systems's population is 2,011.
Milestone Systems's population is 375.
Download Milestone 1.9 (Super Tux 0.3.3): If you have a Windows OS:
Milestone - company -'s population is 16.