1) belonging to history (as contrasted with legend and fiction) (historical)

2) the possession of two contrasted or opposing qualities, principles or tendencies (polarity)

3) the wage-earners in society contrasted with the owners of industry and capital (who are called the bourgeoisie) (proletariat)

4) the use of the body or mind to do or make something (especially contrasted with play or recreation); engage in physical or mental activity (work)