Unless you work in a formal environment or you have to wear a uniform to your job most people wear casual clothes to their place of work. An example of casual clothes may be jeans, a t-shirt and a pair of converse or trainers.
'Everyday clothing' has the same meaning as 'casual clothes'.
The opposite of formal is casual. Therefore, the opposite of formal/smart wear is called casual wear.
For example, you can say:
The first Friday of September is casual Friday. I have to wear casual clothing at work.
"formal"（フォーマル）の反対は "casual"（カジュアル）です。
ですので "formal/smart wear"（フォーマルウエア/礼服）の反対は "casual wear"（カジュアルウエア/ラフな服装）になります。
例えば、次のように言うことが出来ます。
【例文】
The first Friday of September is casual Friday. I have to wear casual clothing at work.
（9月の最初の金曜日はカジュアルフライデーです。職場でカジュアルな服装をしなければなりません）
What you see provided above is what we use to refer to clothing that is the opposite of formal. These are the types of clothing you would use when you are at home or maybe going to the store. These words would be great to practice, especially if you want to go shopping and you are looking for some casual clothing!
If you are describing clothes that are not formal wear then you would call these 'casual clothes/clothing' or 'everyday clothes/clothing'
The term 'rough' is not used to describe this as it does not have such a nice meaning
When talking about clothes that are the opposite of formal, in the UK we would generally describe them as being 'casual'.
"I'm wearingh smart, casual clothes this evening.
フォーマルの反対の服装は、イギリスでは普通'casual'と表します。
例文
"I'm wearing smart, casual clothes this evening."
（今晩はスマートカジュアルな服装で行きます）
イギリス 
日本 
南アフリカ 
アメリカ合衆国 
