inhale; breathe inLiterally means “to breathe in.” Used for intentionally drawing air into the lungs, often in breathing instructions or when describing someone taking a breath. In a sentence, it is commonly conjugated, but this example uses the exact dictionary-form term.
JA: 息を吸うときは、ゆっくり鼻から吸ってください。
EN: When inhaling, please breathe in slowly through your nose.