bel·fry (source : www.thefreedictionary.com)
n. pl. bel·fries
1. A bell tower, especially one attached to a building.
2. The part of a tower or steeple in which bells are hung.
[Middle English belfrei, from Old North French belfroi, alteration of Old French berfrei, berfroi; see bhergh-2 in Indo-European roots.]
Word History: The words bell and belfry seem obviously related, but in fact the bel- portion of belfry had nothing to do with bells until comparatively recently. Belfry goes back to a compound formed in prehistoric Common Germanic. It is generally agreed that the second part of this compound is the element *frij-, meaning "peace, safety." The first element is either *bergan, "to protect," which would yield a compound meaning "a defensive place of shelter," or *berg-, "a high place," which would yield a compound meaning "a high place of safety, tower." Whatever the meaning of the original Germanic source, its Old French descendant berfrei, which first meant "siege tower," came to mean "watchtower." Presumably because bells were used in these towers, the word was applied to bell towers as well. The Old North French alteration belfroi, which reminded English speakers of their native word belle (our bell), entered Middle English with the sense "bell tower," first recorded in 1272.