The metre, kilogram, second and ampere are called fundamental units or base units. From these units we can derive some more units that are called derived units. These units are built up step by step from the base units and usually given a distinct name.
cadre [(kad-ree, kah-dray)] An elite or select group that forms the core of an organization and is capable of training new members. The New Dictionary of Cultural Literacy, Third Edition
Arrears is defined as a situation when a person is behind on a deadline or has an unfinished obligation or business. When a person is behind in their taxes, it is an example of being in arrears. The definition of arrears is a past due debt or an unfulfilled obligation.