A patent basis is a legal concept that allows an inventor to protect their ideas and inventions from being copied or used without permission. The term 'patent basis' is derived from the word 'IDEA, ' which is a four-letter word in this crossword puzzle. A patent is a form of intellectual property that grants exclusive rights to the inventor, allowing them to prevent others from using, making, or selling their invention without their permission. This protection is granted for a limited period of time, usually 20 years.