Physical contact; touching (the act of making contact with something, often written in katakana).
画面に直接タッチして操作してください。
Please operate by touching the screen directly.
子どもがボタンにタッチして、機械が動き出した。
A child touched the button and the machine started.
その犬に不用意にタッチしないでください。
Please don't touch that dog carelessly.
Being involved in something; touching a matter or taking responsibility for it (casual usage).
その問題には私はタッチしていません。
I'm not involved in that issue.
彼は企画段階からそのイベントにタッチしている。
He has been involved in that event since the planning stage.
上司が直接タッチする必要はないと思う。
I don't think the boss needs to be directly involved.
An artist's or musician's touch — the distinctive style, feel, or way of expression (e.g. a pianist's touch).
ピアニストの彼女のタッチは繊細だ。
Her piano touch is delicate.
最近、その画家のタッチが少し変わってきた。
Lately, that painter's touch has changed a bit.
その作家には独特のタッチがあるから、すぐ分かる。
That writer has a distinctive touch, so you can recognize them immediately.
In baseball, a tag: touching a runner to put them out (tag play).
走者が塁に戻ろうとしたが、二塁手のタッチでアウトになった。
The runner tried to return to the base but was put out by the second baseman's tag.
今日の試合はタッチプレーが多かった。
There were many tag plays in today's game.
Childish/kid's term for a 'high five' — slapping palms to celebrate or show joy.
ゴールした彼にみんなでタッチした。
Everyone gave him a high five after he scored.