To get up or rise from a lying or seated position; to stand up or sit up (change from lying/down to upright).
今朝、目が覚めてベッドから起き上がった。
This morning I woke up and got out of bed.
赤ちゃんはやっと自分で起き上がれるようになった。
The baby has finally learned to sit up/stand up by himself.
地震で倒れた人がゆっくりと起き上がった。
The person who had fallen during the earthquake slowly got up.