I consider that it does not extend to recklessness and is therefore narrower than wilful misconduct (although the latter will embrace deliberate default).
[3] Failure to appear at a required time in legal proceedings can constitute a default.
In the United States, for example, when a party has failed to file meaningful response to pleadings within the time allowed, with the result that only one side of a controversy has been presented to the court, the party who has pleaded a claim for relief and received no response may request entry of default.
If this notice is not opposed, or no adequate justification for the delay or lack of response is presented, then the plaintiff is entitled to judgment in his favor.
It dictates that if the money owed (plus an additional legal fee), or other breach(es) are not paid/remedied in a given time, the lender may choose to foreclose the borrower's property.