Wing-span, the distance between the tips of a bird's wings, has several synonyms. One of the most common is "wingspan," which is an alternative spelling of the word. Other synonyms include "wing breadth," "wing length," "wingspread," and "wingtip-to-wingtip measurement." All of these mean the same thing and can be used interchangeably when describing the size of a bird's wings. In addition, terms such as "wingwidth" and "depthing" may be used to describe the distance between the leading and trailing edges of a bird's wings. Regardless of the term used, wing-span is an important measurement for understanding a bird's capabilities in flight.