Please say it once more.
I take a shower once a day during the week, but not at all over the weekend.
Do you want it one more time, honey?
One times is one time. How many times? Just one.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Take note that 一 is shortened (as it often is) to いっ.