The word "厦门" is formed by combining the character "厦", which here functions primarily as a phonetic element representing the local Min dialect pronunciation for the area, with the character "门", meaning "gate", which describes the city's geographical and historical identity as a coastal entrance or portal. The name is believed to have originated from the earlier designation "下门" (lower gate), with the visually similar and more auspicious character "厦" (originally meaning "mansion") later replacing "下" while retaining the similar sound, thus forming the current term "厦门" to signify a "mansion gate" or elevated gateway.