In anime series 'Tonde Buurin' and related media, a minor antagonist is named Goro Tatsumaki/Tatsumaki Goro (竜巻五郎). In this case, the kanji used (五郎) mean 'five' (五) and 'son' (郎). Therefore, it's the 'fifth son' meaning specified in the description for the name.
Gorō Taniguchi is a Japanese anime director, writer, producer and storyboard artist, who is among Sunrise's noted new directors. He was born in Nisshin, Aichi, Japan.
I hope this doesn't offend anyone, but when I hear the name Goro, I instantly think of the evil, four-armed warrior from Mortal Kombat. Not a nice guy.