The letter "þ," known as "thorn," is a character from the Old English and Old Norse alphabets. It represents the "th" sound, as in the words "think" and "that." This unique letter was used in various Germanic languages before gradually falling out of use, replaced by the digraph "th" in modern English. In addition to its linguistic significance, "þ" is often associated with ancient Norse mythology and runes. It symbolizes the connection between language and culture, reflecting how writing evolves over time. Today, "thorn" is mostly found in historical texts and discussions about Old English literature.