What it means
もかまわず expresses doing something without being concerned about, influenced by, or restrained by a particular condition. It commonly follows a noun referring to an obstacle, social judgment, physical condition, or other circumstance. A plain clause can also precede のもかまわず. The expression is somewhat formal and is especially common in writing and serious narratives, but it can also occur in ordinary speech. The politeness of the complete sentence is determined by the main predicate, not by もかまわず itself.
Usage note
Do not confuse もかまわず with てもかまわない, which means that something is permitted or acceptable. In もかまわず, the subject proceeds despite a condition or concern.
How to use it
彼は人目もかまわず、駅前で大声で歌いました。
He sang loudly in front of the station without regard for public attention.
彼は周囲から反対されるのもかまわず、計画を実行しました。
He carried out the plan despite being opposed by those around him.
彼は人目もかまわず、駅前で大声で歌った。
He sang loudly in front of the station without regard for public attention.
彼は周囲から反対されるのもかまわず、計画を実行した。
He carried out the plan despite being opposed by those around him.