The subcutaneous tissues were copiously irrigated, and a few small bleeders were cauterized.

copiously modifies which word?

And your answer is?

were irrigated

To determine which word "copiously" modifies in the sentence, we need to identify the action that is being described as being done to a great extent.

In this case, the action being described is "irrigated," which means that the subcutaneous tissues were cleaned or flushed with a fluid. The word "copiously" describes the extent or amount of this irrigation.

Therefore, "copiously" modifies the word "irrigated." It indicates that the irrigation of the subcutaneous tissues was done abundantly or in a large quantity.