笼 has two readings: lóng (cage, basket) and lǒng (to envelop, to cover, as in 笼罩 lǒngzhào). As a standalone noun meaning cage/basket, it's always lóng.
culture
笼 as a steamer basket is central to dim sum culture. 小笼包 (xiǎolóngbāo, soup dumplings) literally means 'small steamer-basket buns.'
⺮ is the bamboo-top radical (top form of 竹). Cages, baskets and steamer trays were traditionally woven from bamboo strips, so the radical is the literal material. Compare 篮 (basket), 笼's siblings 笼/篓/筐, plus 笆 (bamboo fence), 笛 (bamboo flute).
龙 (lóng) supplies the sound, unchanged. This is the simplified phonetic - traditional 籠 stacked the much heavier 龍 underneath. The 1956 reform swapped in five-stroke 龙. No semantic link to dragons; the dragon just supplies a pure sound match.
