"Clothes for swimming" is an expression you can use when you do not have clothes made specifically for swimming. For example if you use a t-shirt and shorts to go to the pool or beach those are not formal swim wear so you can use this expression.
"Swimsuit or Swimwear" is a phrase used when you are wearing actual clothes made for that purpose for example a bikini or swim trunks for men. This phrase is very popular in the U.S. because most people have proper swimwear.
"Clothes for swimming"
（[泳ぐ](https://eikaiwa.dmm.com/uknow/questions/46489/)ための[服](https://eikaiwa.dmm.com/uknow/questions/36326/)）
この表現は泳ぐために作られた服を持っていないときに使えます。例えば、きちんとした水着ではなくTシャツと短パンでプールやビーチに行く時などにこの表現を使うことが出来ます。
"Swimsuit" or "Swimwear"
（水着）
これは、例えばビキニや男性用の水泳パンツなどの泳ぐために作られているものを言います。大抵の人はきちんとした水着を持っているので、このフレーズはアメリカではとても一般的です。
Swimmers, swimming costume, and swimsuit are all words you can use to describe the clothing you wear when swimming. Swimsuits are usually made from materials such as Lycra, Spandex or Elastane, as they dry very quickly.
In the US, to describe clothing you wear while swimming you would call it a "swimsuit". While in the UK "swimming costume" is used for the clothes that people wear for swimming.
When you're trying to speak about clothes people wear when they are swimming,, you can use the phrases "swimming costume" or "swimwear".
In a sentence, you would use these in the following ways:
-I forgot to bring my swimwear today for the beach.
-I need to get a new swimming costume because my bathing suit is old.
There are certain types of swimwear: bikini, swimming trunks, etc.
泳ぐときに着る水着のことを、 "swimming costume" や "swimwear"といいます。文では以下のように使うことができます。
-I forgot to bring my swimwear today for the beach.
今日ビーチにいくのに水着を持ってくるのを忘れた。
-I need to get a new swimming costume because my bathing suit is old.
私の水着が古いので、新しい水着を買う必要がある。
bikini（ビキニ）, swimming trunks（海水パンツ）などのようにある特定のタイプの水着の言葉もあります。
When swimming there are many names for different kinds of swimwear.
These words for swimwear are about the style of bathing suit.
bikini - standard two-piece bathing suit
trunks - are swimming or boxing shorts that usually come down to just above the knee
string bikini - are bikini's that usually tie behind the neck and back and on the sides of the hips with just strings
Bandeau bathing suits - swimwear that resembles a simple band around the chest
wetsuit - a close-fitting outfit that is for warmth during water sports or diving
speedo - a close-fitting swimsuit or men's tight swimming briefs
What clothes used for swimming may be called really depends on whether they are for men or for women. If they are for women, they may be called 'swimsuits', 'swimming costumes' or 'bikinis'. A swimsuit or swimming costume is normally a one piece item, whereas, a 'bikini' is a two piece item. However, men's clothes for swimming may be commonly called boxer shorts although they may also be called trunks, or board-shorts in Australia .
So, you may say:
Please pack my trunks, I am going swimming.
or
I am going swimming, please pack my boxer shorts
水着の言い方は男か女かによります。女の人の水着は「swimsuit」「swimming costume」または「bikini」と言えます。「swimsuit」「swimming costume」はふつうワンピースで、「bikini」はツーピースです。
一方男性の水着は「boxer shorts」と言うのが一般的です。また「trunks」、オーストラリアでは「board-shorts」と呼ばれることもあります。
Please pack my trunks, I am going swimming.
【訳】水着入れておいて。泳ぎに行くから。
I am going swimming, please pack my boxer shorts
【訳】泳ぎに行くから、水着入れておいて。
女性の「水着」はイギリス英語で「swimming costume」と言います。アメリカ英語で「swimsuit」と言います。男性の「水着」は英語で「swimming shorts」や「swimming trunks」と言います。「swimwear」という広い意味の単語も使えます。
I bought a new swimming costume yesterday.
（私は昨日新しい水着を買いました。）
My husband’s swimming trunks are blue.
（旦那の水着は青いです。）
Excuse me. I want to buy some swimwear.
（すみません。水着を買いたいんですが。。。）
A swimsuit or bathers are clothes that we wear when we go to the beach or pool, when we go swimming.
A bikini is a type of bathers that women wear and it has two pieces.
They put on their swimsuit and went to the beach!
She is wearing a bikini.
Bring your bathers, we are going swimming!
「水着」は英語では「swimsuit」などと言えます。
「swimsuit」は「水着」という意味の名詞です。
ただ、地域による違いもあります。
アメリカ英語では「swimsuit」が一般的です。
〔例〕
I forgot my swimsuit.
→水着を忘れました。
Do you sell swimsuits?
→水着売ってますか。
ご質問ありがとうございました。
水着は英語でswimsuit又はswimwearと言います。
Swimsuitは水着の一着を意味する言葉です。
水着の一般はswimwearと言います。
例）
今度の旅行のために水着を買わなきゃ
I need to get a swimsuit for the trip
（店で）水着はどこですか？
Where is the swimwear?
婦人水着
Ladies' swimwear
ご参考になれば幸いです。
水着は色んな言葉があります
- swimsuit
- bathing suit
- bikini
- swimwear
海行くから新しい水着買えないと
I need to buy a new swimsuit because I’m going to the beach
その水着はエロすぎから他のにする
That bikini is too sexy so ill go with another one
水着は英語で swimsuit や swimwear などと言います。
swimsuit は上下一体型の水着になります。
したがって男性用の水着なら swimwear と言います。
I’d like to buy a new swimsuit before summer.
夏前に新しい水着を買いたいです。
日本 
アメリカ合衆国 
オーストラリア 
南アフリカ 
イギリス 
ミャンマー 
