Reading: KYU / kiwameru
Etymology: Interestingly, the combination of the crown radical, meaning hole, and the lower radical, meaning nine, gives us bent elbow (!).
Supposedly it comes from the image (permanently stuck in my mind) of someone going to extreme measures to get something out of a hole (now it's stuck in your mind too:-).
Mnemonic: EXTREME INVESTIGATION OF NINE HOLES
研究 - Research
(Based upon Henshall, 1998).