Waki ga Amai (脇が甘い - Vulnerable)

Waki ga Amai

To describe that someone's defenses are weak or someone is vulnerable, you can say the Japanese idiom 'waki ga amai' (脇が甘い).

'Waki' (脇) means "armpit" and 'amai' (甘い) means "sweet" or "lax," so the literal meaning of 'waki ga amai' is "one's armpit is sweet" or "one's armpit is lax."

Of course, it does not literally mean that someone's armpit is sweet.

This idiom comes from a traditional Japanese sport, 'sumō' (相撲).

In sumō, if you do not close tightly your armpits, you will be thrown and defeated.

Because of this, 'waki ga amai' came to have its current meaning.

脇が甘い

守りが弱いことや、用心が足らず相手につけこまれやすいことを、「脇が甘い」と表現します。

「脇」は "armpit"、「甘い」は "sweet" や "lax" を意味するので、「脇が甘い」の文字通りの意味は "one's armpit is sweet" や "one's armpit is lax" となります。

しかし決して、"someone's armpit is sweet" という意味ではありません。

この慣用句は、日本の伝統的なスポーツである相撲に由来します。

相撲では、脇をしっかり締めていないとまわしを取られてすぐに負けてしまいます。

このことから、「脇が甘い」は現在の意味を持つようになりました。

• This idiom comes from a traditional Japanese sport, 'sumō' (相撲).
• This idiom comes from the traditional Japanese sport, 'sumo' (相撲).

  There's only one sumo, at least in English speakers' knowledge.
  
  While sumō would technically be the correct translation, we just use sumo in English.

• In sumō, if you do not close tightly your armpits, you will be thrown and defeated.
• In sumo, if you do not tightly close your armpits, you will be thrown and defeated.

  Adverbs usually come before the verb... Usually.

• Because of this, 'waki ga amai' came to have its current meaning.
• Because of this, 'waki ga amai' came to have its current meaning.

  A phrase sometimes used when describing something is:
  
  "And thus, "〇〇" was born." or "And that's how 〇〇 got its name."

Great writing! Very interesting stuff :)