What does a "slow healing wound" mean? how slow is slow?

Slow healing wound: Our body has an innate ability to heal and most of simple wounds heal without any complications.But some wounds are slow to heal either due to complications of the wound, depth, infection etc and it takes longer to heal.It can also be due to other medical conditions like diabetes, varicose veins and poor state of health of the person.How slow is variable from few days to few weeks and months.