Describes something that has a distinctive, one-of-a-kind quality, often with a nuance of being unlike anything else. Used as a な-adjective.
His paintings have a unique charm.
The atmosphere of this shop is peculiar.
独特 means 'unique' or 'distinctive' in a general sense. 一種独特 adds emphasis, meaning 'a kind of unique' or 'peculiarly distinctive', often implying a more idiosyncratic or unusual quality.
Standard kanji spelling.
Variant using 得 instead of 特; less common.
Compound of 一種 (one kind) and 独特 (unique, peculiar). The combination reinforces the idea of a singular, distinctive quality.