a clause in a contract that provides for an increase or a decrease in wages or prices or benefits etc. depending on certain conditions (as a change in the cost of living index)
source: WordNet 3.0
a stairway whose steps move continuously on a circulating belt
source: WordNet 3.0
A stairway or incline arranged like an endless belt so that the steps or treads ascend or descend continuously, and one stepping upon it is carried up or down; -- a trade term.