slightly
聊 centers on a small degree or slight extent: something that is only a little, barely, or insignificantly so.
聊 combines 耳 (ear) with 卯, which likely contributes the sound. The exact historical development of the meaning 'slightly' from these components is uncertain.
The ear 耳 catches only a slight whisper from the right side 卯, so 聊 means 'slightly' or just a little bit.
For リョウ, imagine a slight, barely audible sound like a soft 'ryo' whisper entering the ear: ryo -> リョウ, and it's only slightly heard.