decimated

An attack or loss that reduces something by one tenth can be called decimated. This means that ten percent of something is lost.

When we talk about something being decimated, it usually refers to a big drop or reduction in number or size. For example, if a business loses customers and profits are down by 10%, people might say the company's sales were decimated. It can also refer to the loss of a significant portion of a group, like when an army is attacked and ten percent of its soldiers die. In this case, we'd say the army was decimated.

In some cases, "decimate" can be used as a verb or noun, but it's often considered more formal or old-fashioned than other words with similar meanings, like "reduce" or "destroy".