訓 も(える),も(やす) ・ 音 ネン
漢越音: nhiên
然 already meant burning (those four dots 灬 are fire), but it got borrowed for the abstract sense "thus", so a second 火 was bolted on. Hence nenryou, fuel.
Stroke data: KanjiVG (CC BY-SA 3.0) — kanjivg.tagaini.net
ここでごみを燃やしてはいけません。 (ここでごみをもやしてはいけません)
You must not burn trash here.