The first name Sydney is ♀ female and ♂ male.
Sydney is a form of Sidney. Sydney was originally a surname. Besides, it is a variant of Sidony, an anglicised form of Sidonia. And it is of course the name of the largest city in Australia.
Sydney means “wide/broad island” (from Old English “sīd” = broad/wide “īeg” = island) and “of Sidon”.