Inconvenient; something that is impractical, awkward, or causes trouble.
この駅は出口が少なくて不便だ。
This station is inconvenient because it has few exits.
山間部では携帯が通じないのでとても不便だ。
It's very inconvenient in the mountains because mobile phones don't get reception.
紙でしか申し込めないのは現代では不便だと感じる人が多い。
Many people find it inconvenient these days to be able to apply only on paper.