One way to hold these meanings together: picture something being spent a little at a time, with nobody adding anything back. Each month there is slightly less than there was. On a body, what goes is flesh and strength. On property, what goes is value. The word never tells you the cause, and it never means a sudden drop — it names the slow, one-way direction of travel.
Two branches
身體被慢慢耗掉
被一點一點花掉的東西是身體：肉少了，力氣跟著少。
adjective · C1
Used in 'a wasting disease' or 'a wasting illness': a long illness that slowly takes flesh and strength out of the body, so that the person becomes thinner and weaker as the months or years pass.
消耗性的（疾病）
價值被慢慢耗掉
同樣是一點一點被花掉，只是這次少掉的是錢和價值，不是肉。
adjective · C2
Used in 'a wasting asset': something a company or a person owns — a building, a business, a licence — that is steadily losing money or losing its value, so it is worth less as time passes.
價值遞減的（資產）
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
wastingadj/ˈweɪstɪŋ/
Causing a waste, or wasting away; causing pronounced loss of body mass.
wastingnoun/ˈweɪstɪŋ/
Gradual deterioration or wasting away.
The act by which something is laid waste; destruction.
這個拼法也被記錄為下列字的變化形：
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。