How to Say "Smooth" in Japanese

滑らか

nameraka

The English word "smooth" is translated into Japanese as 滑らか (nameraka).

滑らか is used to describe something that lacks friction, is not rough.

Meaning: lacking friction, not rough (adj)

Which one should you use?

While 滑らか refers to texture or flow, another word, スムーズ (sumūzu), is often used for smooth processes or transitions in modern Japanese.

The adverbial form is created by adding に to the stem.

nameraka

In Japanese slang, 滑る (the root of 滑らか) is used when a joke 'flops' or fails to get a laugh, implying the joke 'slipped' past the audience.
While English uses 'smooth' for both a smooth surface and a smooth personality, Japanese might use 物腰が柔らかい (monogoshi ga yawarakai), meaning 'soft in manner', to describe a smooth social interaction.
The kanji in 滑らか, namely 滑, contains the radical for 'water' (氵), which hints at the slippery, fluid nature of the word.

彼女の肌は滑らかです。
Her skin is smooth.
This sentence is useful for describing how smooth the form 滑らか applies to skin.
Tatoeba #94083 by huizi99, translation #309622 by CK
列車は滑らかに停止した。
The train came to a smooth stop.
This sentence is useful for showing how the form 滑らか describes the motion of a train stopping.
Tatoeba #77501 by arnab, translation #326218 by CK
この布は滑らかな手触りです。
This cloth feels smooth.
This sentence is useful for describing the tactile sensation of cloth using the form 滑らか.
Tatoeba #220081 by mookeee, translation #57400 by CK
このプロジェクトはスムーズに進んでいます。
This project is progressing smoothly.
その塗りは滑らかで美しい。
The painting is smooth and beautiful.
この道はなめらかな走り心地です。
This road has a smooth ride.
このリップクリームは唇をなめらかにする。
This lip balm makes your lips smooth.
2 more sentences on Tatoeba

At an art gallery, Misaki and Hiroto are looking at a sculpture.

美咲 Misaki

この彫刻、表面がとても滑らかだね。
kono chōkoku, hyōmen ga totemo nameraka da ne.
This sculpture has a very smooth surface, doesn't it?
大翔 Hiroto

本当だ。指が滑りそうなほどだよ。
hontō da. yubi ga suberisō na hodo da yo.
Truly. It's so smooth my fingers might slip.
美咲 Misaki

大翔君の感性は鋭いね。
hiroto-kun no kansei wa surudoi ne.
Hiroto, you have a sharp sensibility.
大翔 Hiroto

美咲さんに褒められると嬉しいよ。
misaki-san ni homeraru to ureshii yo.
I'm happy to be praised by you, Misaki.

Sources

⭐Share⭐ to appreciate human effort 🙏