inopportune

adj

1. Unsuitable for some particular purpose.

   “That was a most inopportune spot for a picnic.”

   “"It appears I come at an inopportune time, madam," said he, "when my friend, Mr. Rochester, is from home; but I arrive from a very long journey, and I think I may presume so far on old and intimate acquaintance as to install myself here till he returns."”

2. Happening/occurring at an inconvenient or inappropriate time.

   “The inopportune arrival of the bus cut short the interesting conversation.”

   “The object is to keep the yard operators apprised of main-line movements, so that they do not plan to occupy the main lines with activity into or out of the yard at an inopportune juncture.”