This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
欗 combines 木 (tree/wood) with 蘭, which likely contributes the sound. The exact historical development is uncertain.
The left side is 木 (tree/wood), and the right side is 蘭 (orchid). Picture a wooden railing entwined with orchids, hinting at the kun reading てすり (handrail).
For ラン, imagine a wooden railing covered in orchids: the orchid 蘭 cues ラン, and the wood 木 makes it a handrail.