Definition from Wiktionary, the free dictionary
Ancient Greek μέτρον
metron (plural metrons)
- measure (poetic)
- (by extension) sphere of influence
- (physics) A two-dimensional quantum of multidimensional space, a unit of measure in Heim theory.
- "People are taught to understand their orbit of influence not their position... As long as every person understands their own metron and stays within their orbit, you have little problems. Everyone keep rank and do what is expected from them..."
- "Grace, favour, and everything we need to be successful in ministry are given to us to accomplish our task when we are within our metron."
- Ref: CLARK. Advanced Apostolic Studies: Transitioning Every Believer into Apostolic Ministry. Spirit of Life Ministries, 2008. ISBN 9781886885172.
- "We, however, will not boast beyond [our metron], but within the limits of the sphere which God appointed us—a sphere which especially includes you. For we are not overextending ourselves (as though our authority did not extend to you), for it was to you that we came with the gospel of Christ."
- Ref: "The Holy Bible": 2 Corinthians 10:13-14 
Related terms 
- accusative singular of metro
- Genitive singular form of metro.