To be pertinent
To cause anxious uneasiness in
Something that concerns or involves one personally
A cause of distress or anxiety
Curiosity about or attention to someone or something
The quality or state of being important
A troubled or anxious state of mind
A commercial organization
A small specialized mechanical device
To have reference to
To make uneasy
So there's no concern these visions may stop completely?
Apparently his greatest concern was the fact that his mother was married to his adoptive father at the time he was conceived.
His main concern is security: "You don't know who the buyer is."
We must have a concern for the welfare of zoo animals.
However, it begged the question of what had caused the old guy so much concern in the first place.