Umbrella Stand
Umbrella Holder
noun
This is when you take your umbrella and you stand it up. Wait, how is an umbrella standing up? Good question, my dear Crabling, you are putting your umbrella in an umbrella stand.
かさたて
The reading is the readings for 傘 (learned with the kanji) and 立つ (to stand).
傘立てに濡れた傘を立てないで下さい。
Please do not put a wet umbrella in the umbrella stand.