[粵拼: dei6 haa6 | 漢語: di4 xia4]
(less used in spoken Cantonese)
[1] underground; subterranean [2] (fig.) secret; secretive; underground (activities, etc.)

[粵拼: dei6 haa62 | 漢語: di4 xia5]
(more frequent in spoken and written Cantonese than in written Chinese outside HK / Macau, or in spoken Mandarin)
[3] on the ground; on the floor | 漢: 地面 [4] the ground floor, GF | 漢: 底層 | Syn.: 一樓

[] Note: There is considerable confusion as HK addresses often have '地下' in their description indicating 'Ground Floor' whereas mainland Chinese establishments use '地下' to indicate the basement floor; e.g., '地下二樓' means 'Basement Level 2'. HK Chinese uses '地庫' for 'basement'