Gross negligence is the "lack of slight diligence or care" or "a conscious, voluntary act or omission in reckless disregard of a legal duty and of the consequences to another party.
By extension, if somebody has been grossly negligent, that means they have fallen so far below the ordinary standard of care that one can expect, to warrant the label of being "gross".
[7]This view has been consistently approved in English law relating to fiduciary duties, as the courts have reasserted that there is only one standard of culpable carelessness: ordinary negligence.
The preferred view has been that the context of a trustee, company director or other fiduciary's judgment is to be taken into account when the judge reviews the exercise of discretion.
It was held that exclusion clauses were still effective (though other remedies could follow, such as UCTA 1977 in a contract law case) but on the point of principle, as a default position all trustees are liable for ordinary negligence.
The doctrine of the common law is that: "Gross negligence may be evidence of mala fides, but is not the same thing": see Goodman v. Harvey (1836) 4 A.
Roman lawyers had an axiom that gross negligence amounts to an intentional wrong, or culpa lata dolo aequiparatur.