Look up votive church in Wiktionary, the free dictionary.
A votive church (votive from the Latin votum 'vowed sacrifice, vows') is a church that was built as a sign of thanksgiving for salvation from an emergency or with a request for the fulfillment of a specific desire, and sometimes atonement (also known as an "expiatory chapel"). Often, the builder has previously made a vow to have the church built in the case of the prayer heard (takeover of the construction costs). Votive churches also include so-called thanksgiving churches: