old school

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A group that adheres to traditional ideas or practices.

from The Century Dictionary.

• Of the old school; of earlier times; as originally or formerly established, propounded, or professed; old or old-fashioned.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective informal, idiomatic Characteristic of a style, outlook, or method employed in a former era, remembered either as inferior to the current style, or alternately, remembered nostalgically as superior or preferable to the new style, the older denoting something that would be considered out of date or out of fashion to some, but as such, is considered by others as cool and hip.
• noun informal, idiomatic A style, way of thinking, or method for accomplishing a task that was employed in a former era, remembered either for its inferiority to the current method, or for its time-honored superiority over the new way.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a class of people favoring traditional ideas