When plants get water, how long does it take for them to absorb it?
You suck something in and obtain it. Shhheewwwwww! When you suck something in and obtain it into your body, you have done absorption because it's been sucked inside of you.
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.