This is the 420th most frequent Dutch word.
overigens
"Moreover," "besides," or "by the way."
Here, "overigens" is used to introduce a side remark or additional information related to the conversation without being its main point.
Ik heb dat boek overigens al gelezen.
By the way, I have already read that book.
In this case, "overigens" serves to contrast or correct a previously stated idea or assumption.
Ze zijn overigens erg vriendelijk, ondanks de eerste indruk.
They are, however, very kind despite the first impression.
In this context, "overigens" is used to point out an additional viewpoint or fact that supports or elaborates on the current discussion.