A situation in which the law considers someone as having notice of a particular fact because they knew of sufficient other facts such as would cause a reasonable person to make inquiries and then gain additional knowledge.
Example: Zack finds a house he wants to buy. The owners live out of town, but every time Zack visits the house to review and inspect it, he sees evidence that someone is living in the house. Despite that, he signs a contract to buy the house, goes through with the closing, and is surprised when the current tenants tell him they have a 5-year lease on the property. Zack had implied notice of this fact. When he saw evidence of occupancy, he should have asked more questions and is not entitled to simply sit in ignorance and hope everything works out for the best.