To try to improve one's social or financial status by marrying into or associating with people of higher standing; to attach oneself to someone influential.

To curry favor with influential people; to social climb or marry above one's social status.

To improve one's social status by marrying or associating with people of high rank or power; to attach oneself to a bigwig.

To curry favor with or marry into a family of higher social status or wealth.

(literary) high branch; (figuratively) a superior place, an influential person, or a high social position