Several parts combine into one character.

The traditional 帶 was a pictograph showing a waist-belt with ornamental items hanging from it — a sash plus the keys, charms, and pouches that hung from the belt of an ancient Chinese gentleman. The original character preserved the entire dressing tableau. Three CJK regions then simplified differently: traditional Korea retains 帶, Japan adopted 帯, Mainland China uses 带. From the concrete waistband image, the meaning radiated outward: belt → wrap around → carry along with you → zone (a band-shaped region like a tropical or frigid zone).

Korean reading "dae." 帶同 (daedong, accompany / take along), 寒帶 (handae, frigid zone), 熱帶 (yeoldae, tropical zone — basic geography), 一帶一路 (ildae-illo, "One Belt One Road" — the official Korean rendering of China's Belt and Road Initiative; political/economic news term), 連帶 (yeondae, solidarity — "linked-together belt"), 包帶 (bungdae, "wrapping band" = bandage — medical).

Mandarin dài, 4th tone (simplified 带). 带 (dài, belt / to bring along), 携带 (xiédài, to carry — formal), 一带一路 (yīdài yīlù, "One Belt One Road" — the geopolitical signature initiative of the Xi Jinping era), 热带 (rèdài, tropical zone), 磁带 (cídài, "magnetic belt" = magnetic tape, audio cassette). Critically, 带 functions as an everyday verb meaning "to bring / carry": 带钱 (dài qián, bring money), 带孩子 (dài háizi, to look after children — literally "bring along the child"). The verb usage is among the most common in Mandarin.

Japanese on-reading タイ (tai) — 携帯 (keitai, "portable" — the Japanese word for mobile phone; ケータイ in katakana is the most common form), 熱帯 (nettai, tropics), 連帯 (rentai, solidarity). Kun-readings: おび (obi, the broad sash worn around the waist of a kimono — one of the most distinctive components of traditional Japanese dress, often more elaborately woven and more expensive than the kimono itself); おびる (obiru, to wear a sash / to bear / to take on — used metaphorically: 重要性を帯びる "to take on importance"). The kimono obi is to Japanese clothing what the codpiece or cravat once was to Western dress — a focal accessory that defines the outfit's formality.

Memory aid: a waist-belt with ornaments hanging — sash, by extension wrapping, carrying, and zone-like regions.