A question on nowhere dense sets.

This is based on an old (early 20th century) usage (gone mostly out of style) to call a set $A$ "somewhere $P$" if there is some non-empty open set $O$ such that $O \cap A$ has property $P$ in $O$ (somewhere = 'inside some non-trival open set') and a set that is "not somewhere dense", was called "nowhere dense" for short. This only explains the origin of this specific name. The definition is useful because of its connection to Baire's theorem and meagre sets.