burn, bonfire
燎 centers on fire used for burning or as a large outdoor flame: a bonfire or the act of burning something in a blaze.
燎 combines 火 (fire) with 尞, which likely contributes the sound and may relate to burning or a high flame. The exact origin of 尞 is uncertain.
Fire 火 on the left, and the right side 尞 looks like a tall structure with a top and base. Picture a big bonfire with flames leaping high: 燎 is a bonfire or burning blaze.
For リョウ, imagine a row of bonfires lighting up the night: row -> リョウ, and each fire burns brightly.