The definition of an institution is an established custom or practice, or a group of people that was formed for a specific reason or a building that houses the group of people. Marriage is an example of a cultural institution.
Contextual targeting is a type of targeting on the Google Display Network in which you select specific keywords or topics and then allow AdWords to identify websites that are a good fit for your keywords and targets.
contextual definition - a definition in which the term is used by embedding it in a larger expression containing its explanation; a contextual definition of `legal duty' might be `X has a legal duty to do Y means that X is required to do Y by a contract relationship that would be upheld in a court of law'.