This pattern means 'without caring about' or 'regardless of.' It describes an action done while ignoring something that would normally be a concern, such as appearance, time, or other people's feelings. It often carries a nuance of being reckless, self-absorbed, or intense.

It is a somewhat formal and literary expression, more common in writing than in casual speech. In conversation, you'd often hear phrases like '～を気にしないで' instead. When used, it often pairs with the particle も attached to a noun, or with the past tense of a verb to show that something happened and was ignored.

The tone is neutral but can imply criticism or admiration depending on context. For example, someone working hard without caring about time might be praised, while someone ignoring others' feelings might be criticized.