Gaining knowledge of something is an important part of life. Learning is a process that involves acquiring new information, understanding it, and applying it to our lives. The term 'gain knowledge of' can be used to describe the process of learning something new. In this context, the crossword solutions for the term 'gain knowledge of' are 'LEARN, ' which is a five-letter word. Learning is a lifelong process that can help us grow and develop as individuals.