Imperfect; incomplete; having defects or shortcomings and not reaching a complete or fully correct state.
設計図はまだ不完全なので修正が必要だ。
The blueprint is still incomplete, so it needs revision.
不完全なデータで結論を出すのは危険だ。
It's risky to draw conclusions from incomplete data.
彼の日本語は不完全だが、会話には支障がない。
His Japanese is imperfect, but it doesn't interfere with conversation.