What does rasengan mean in japanese?

It is written 螺旋丸. Consists of three kanji, from left to write the first two read together as /ra zen/ meaning 'spiral, coil, helix' and the third is kanji for 'ball' and reads /ma ru/ if single. But in compound noun such as this it reads /gan/. Together they mean 'spiraling ball'.

Also 'Naruto' itself if written with this kanji "鳴戸" can mean 'maelstrom'. Alternatively 'Naruto' originally refers to the sliced cakes with fish paste used in ramen, which also has a 'spiraling' shape on the side of it. 'Uzumaki' as well, written 渦巻き can mean 'whirlpool, coil' and the sign of the clan Uzumaki is a coil-like shape on the back of his clothes.