竲

It means a high, roofless tower. The earliest surviving dictionary entry for 竲 is in the Han-era Shuowen Jiezi, an early Chinese character dictionary compiled 100–121 CE; that dates the book, not the character’s first use. The entry describes a high tower in the north.

The Book of Rites, an ancient Chinese work on ritual, describes 橧巢 as a raised summer shelter made by piling wood, in a passage about life before houses. A note in the Shuowen Jiezi records 竲 as an alternate writing of 橧 in that phrase. Later dictionaries also gloss 竲 as “high” or “lofty.”