the english family name durnall is classed as being of habitation origin i.e. derived from either the location of the place of residence of from the name of the town or village that they came from.There is a plant called the "darnel" plant, but there is also a place name Darnall. There is mention of a John Durnell in the US who recieved a Revolutionary War Pension in April, 1807.In 1819, the soldier lived in Delware County, Pennsylvania. Variants - Durnall, Dernel, Dernell, Darnal, Darnol. Any more info. would be appreciated.