This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
爤 combines 火 (fire) with 蘭, which likely contributes the sound. The exact historical development is uncertain.
The left side is fire 火, and the right side is 蘭 (orchid). Picture an orchid being burned by fire, but the meaning remains uncertain.
For ラン, imagine a rare orchid (ラン) catching fire: the orchid's name ラン cues the reading while the fire 火 burns.