We introduce a novel set-intersection operator called 'most-intersection' based on the logical quantifier 'most, via natural density of countable sets, to be used in determining the majority characteristic of a given countable infinite collection of systems. The new operator determines based on the natural density, the elements which are in 'most' sets in a given infinite collection. This notion allows one to define a majority set-membership characteristic of an infinite collection with minimal information loss, compared to the standard intersection operator, when used in statistical ensembles. We also give some applications of the most-intersection operator in formal language theory. The introduction of the most-intersection operator leads to a large number of applications in pure and applied mathematics.