限界 (genkai) means “limit” | MotiTan Japanese Dictionary

More examples

これ以上続けると、限界を超えてしまいます。ko re i jō tsuzu ke ru to gen kai o ko e te shi ma i ma su

If we continue any longer, we will go beyond the limit.

Shows the point beyond which an amount, ability, or effort cannot go.

限度gendo: The maximum amount or degree that can be accepted or reached.
上限jōgen: The uppermost amount or level established for something.

それ以上は進めない、増やせない、または耐えられない境目。so re i jō wa susu me na i fu ya se na i ma ta wa ta e ra re na i sakai me

限 (gen, "limit") supplies the sense of restriction, and 界 (kai, "boundary") adds a dividing edge, together giving the sense of a final boundary.

English learners may hear 限界 (genkai) in statements about work, study, or tiredness, where it means that continuing has become impossible rather than merely difficult.