From previous number + つ words, you can probably guess that this word means five things.

The reading of this word is the kun'yomi reading of the kanji 五, meaning you didn't learn it when you learned the parent kanji reading. To remember this word, think of it this way:

You have five things. What do you have to do with them? You need to eat (いつ) them. Just imagine having five delicious things to eat, sticking each on one finger of your hand, and then eating them one after another. And make sure to count down from five while doing it!