いちがい一概ichigaini
1.

In a manner that disregards specific differences and treats all instances uniformly, often used in contexts where such generalization may be misleading or overly simplistic.

2.

In a way that entails making a judgment or declaration about a group without considering individual variations, typically accompanied by negative implications regarding the validity of such conclusions.

3.

Without differentiating individual cases or conditions, leading to a broad, sometimes inappropriate, categorization or assumption about a particular subject or situation.

Example:

そうですね。一概には言えませんね。