unpunctual

From un- +‎ punctual.

unpunctual (not comparable)

1. Not punctual.

   Jim was so unpunctual — always late!

   • 1947 November and December, Lord Garnock, “A Swiss Railway Miscellany”, in Railway Magazine, page 341:

     Indeed, the only unpunctual trains appear to be some of the International ones, and with these, if they are likely to be over an hour late reaching the frontier-station, the Swiss run their own train over the route provided the International express was being used for inter-communication with Switzerland.

• unpunctually
• unpunctualness