In Mandarin Chinese, 冬 (Pinyin: dōng 🔊) is a noun that means “winter”. 冬 is also an alternative form of 咚, an onomatopoeic word that could be translated as “rat-a-tat-tat” (if it is a repeating sound like knocking on a door) or “bang”, “boom”, “thud”, “thump” (if it is a sound of something falling).
As for the origin of 冬, Lawrence J. Howell in his Etymological Dictionary of Han/Chinese Characters provides the following explanation:
Originally, a depiction of food tied to a cord that winds about a peg. A seal inscription form adds 氷 ice → winter (season when preserved / stored food is consumed). Compare 蓄.More photos related to winter and sea glass @ Shutterstock.