Noble

Noble is a state-privileged status which is generally hereditary. Titles of nobility are usually associated with present or former monarchies. The term originally referred to those who were "known" or "notable" and was applied to the highest social class in pre-modern societies.

One Piece
Nobles are not to be confused with World Nobles as nobles are people restricted to their respective kingdoms while the World Nobles are people who were descendants from the Twenty Kingdoms and live only in Mariejois.

A majority of the nobles shown in the series have been shown to be heartless. In particular, the nobles from Goa kingdom deciding to have Gray Terminal burned and shoot the people living there who tried to escape to make the kingdom beautiful for the visiting World Nobles, in hopes to be given a step up in their Noble status. All nobles have been shown to be very cowardly, where despite their fearsome reputation they often cower to any threat of physical violence.

Currently the only people to whom this has not stretched to would be the rulers of the Kingdom of Alabasta, who truly care deeply for their people despite the differences in status and fight to protect them, going as far as self-sacrifice. Wapol's Father, and later his successor Dalton, also only cared for the well-being of their people, and are loved by the kingdom in return. Sabo, who is deeply disgusted by the way Nobles act and wishes to have his status as one revoked, is another prime representation of a "kind" Nobility.