A point in time representing a key or important intermediate event in the life of a project. A milestone should be capable of validation by meeting all of the items prescribed in a defining checklist as agreed with the stakeholders.
(Wideman Comparative Glossary of Common Project Management Terms v2.1)
I am ex-architectural woodworker and general contractor turned IT, Business and Project Management consultant, software developer wannabe senior division triathlete and ski racer, Yankee fan and founder of Paradigm-360.com, 360 Difference Mac4Construction.com,iOS4Construction.com and now TheBuildingAndRemodelingWiki.com too.