This character is a Other Letter and is mainly used in the Hangul script. The character is also known as D.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it is written from left to right. When changing direction it is not mirrored. U+1103 forms a Korean syllable block with similar characters, which prevents a line break inside it. The glyph can be confused with 43 other glyphs.
The Wikipedia has the following information about this codepoint:
Digeut (sign: ㄷ; South Korean: 디귿, digeut; North Korean: 디읃, dieut) is a consonant in the Korean alphabet. The Unicode for ㄷ is U+3137. Depending on its position, it makes a 'd' or a 't' sound. In an initial or final position in a word, the pronunciation is usually [t], while after a vowel it is pronounced [d], for example in the word deudieo (드디어, "finally"), the initial ㄷ is [t], while the second ㄷ is [d].