• 裏口うらぐち — back entrance
• 裏切うらぎる — to betray
• 裏面りめん — reverse side (of paper, etc.)
• 裏話うらばなし — behind-the-scenes story
• 裏表うらおもて — double-sided; two-faced

裏 combines 衣 (clothing) with 里 (interior), evoking “the inside/back of clothing”—and by extension, what’s behind or hidden. It’s used both literally (reverse side) and figuratively (secrets, betrayal).