To Make Someone Wait, To Keep Someone Waiting
transitive verb, ichidan verb
This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means wait so this word has something to do with waiting. Use the たせ as a hint. Someone "tossed" a ball off into a ditch, and then they had to find it. They made you wait for them to get the ball too, even though it's a cheap piece of crap. Feel upset about this. That'll help you remember that this means to make someone wait and to keep someone waiting.
またせる
You learned this reading from 待つ, congrats!
人を待たせるのは良くないよ。
It's not good to keep people waiting.
一体いつまで待たせるつもりですか?
How much longer are you going to make me wait?
お待たせしてすみません。いや〜バスにえらく長いこと待たされましてね。
Sorry for making you wait so long. I had to wait for the bus for such a long time.