Several parts combine into one character.

森 stacks three trees: 木 + 木 + 木 — three trees becomes a deep, dense forest. The script's "tree-ladder" runs cleanly: one tree (木) → grove of two (林) → forest of three (森). This is the most beautiful demonstration of doubling/tripling as a productive principle in CJK characters. Identical across 繁體 / 新字体 / 简体.

The meaning extends beyond the literal forest into "dense, austere, awe-inspiring": 森厳 (shínyán / shingen, solemn / strict), 阴森 (yīnsēn, gloomy / spooky), 森羅万象 (shēnluó wànxiàng / shinra banshō, "everything in the universe" — everything spread out like a forest). When you see 森 in an abstract compound, expect "vast and dense".

Mandarin: sēn, level 1st tone. 森林 (sēnlín, forest), 阴森 (yīnsēn, eerie / forbidding — the dark-feeling of a deep forest), 森严 (sēnyán, strict / heavily guarded — "forest-strict"). Note the same character lends itself to both natural beauty (森林) and emotional gloom (阴森).

Japanese: on-reading シン (shin) appears in 森林 (shinrin, forest) and the practice 森林浴 (shinrin-yoku, forest bathing). Kun-reading もり (mori) is the everyday word — and crucially, it is one of the most common Japanese surname components: 森 (Mori), 森田 (Morita), 森本 (Morimoto), 大森 (Ōmori, "big forest"), 青森 (Aomori, "blue forest" — a prefecture in northern Honshū). Almost every region of Japan has a 森-prefixed place name.

In Japanese mythology and Shinto, gods (神 kami) traditionally dwell in deep forests, and many shrines (神社 jinja) are surrounded by 鎮守の森 (chinju no mori, "guardian forests") — sacred groves preserved for centuries.

Memory aid: three trees, one above two — a forest growing in pyramid form.