Several parts combine into one character.

凍 is a phonetic-semantic compound: 冫 (the "ice" radical, two stylized ice crystals) + 東 (dōng, "east" — providing the sound). The semantic logic is precise: "to take on the crystalline structure of ice" = to freeze. The 冫 radical is the great organizer of cold-related vocabulary in CJK: 凍 (freeze), 冷 (cold), 凜 (chilly / awe-inspiring), 涼 (cool), 冬 (winter), 凝 (congeal). Notice how 冫 has only two strokes versus the three of 氵 (water) — those two strokes are crystal points, marking the phase change from liquid to solid. Mainland simplified to 冻.

Korean reading "dong." 凍結 (donggyeol, freezing — used in finance for "frozen assets" 자산동결 and in geography for permafrost), 凍傷 (dongsang, frostbite), 解凍 (haedong, thawing — used both for food defrosting and for political thaw), 凍土 (dongto, frozen earth / tundra), 急凍 (geupdong, quick-freeze). The pair 凍結 / 解凍 (freeze / thaw) is alive across financial, biological, and political vocabulary.

Mandarin dòng, 4th tone (simplified 冻). 冷冻 (lěngdòng, frozen / refrigerated), 解冻 (jiědòng, thaw), 冻肉 (dòngròu, frozen meat), 冻得发抖 (dòng de fādǒu, "frozen to shivering"). The proverb 冰冻三尺非一日之寒 (bīngdòng sān chǐ fēi yī rì zhī hán, "ice frozen three feet thick is not the work of one day's cold") describes anything that took long preparation to achieve — used in business and political analysis to mean "this didn't happen overnight."

Japanese on-reading トウ (tō) — 凍結 (tōketsu, freezing), 冷凍 (reitō, frozen — used for 冷凍食品 reitō shokuhin "frozen foods" in supermarkets), 凍傷 (tōshō, frostbite), 解凍 (kaitō, thawing). Two kun-readings split human and material freezing precisely: 凍る (kōru, "to freeze" — applied to objects, water, food) versus 凍える (kogoeru, "to be numb with cold" — applied to a person's body in cold weather). The first is what happens to a pond; the second is what happens to your fingers. Mixing the two sounds odd in Japanese — 私が凍る would mean "I literally turn into ice."

Memory aid: ice radical (冫) plus east (東 just for sound) — taking on the form of ice = freezing.