Final answer:
Adverse possession is a legal concept that allows a trespasser to gain ownership of property by using it for a certain period, under specific conditions.
Step-by-step explanation:
The term defined as someone claiming property of another simply by using it for an extended period of time is known as adverse possession. Adverse possession allows a trespasser to gain legal ownership of property if they openly inhabit and use it for a certain period of time, effectively excluding the actual owner. The process of adverse possession can be complex and typically requires the possessor to fulfill specific requirements, including the use being hostile, actual, open and notorious, exclusive, and continuous for a statutory period. This concept plays a critical role in property law and can result in a change of ownership without the original owner's consent.