This text covers a wide range of communication disorders, including developmental language disorder, autism spectrum disorder, aphasia, normal aging, and dementia. It illustrates the connections between the research evidence and clinical practice and addresses lexical learning and retrieval difficulty through a holistic lens and cognitive-linguistic frameworks. This text integrates research evidence from a variety of disciplines, including speech-language pathology, linguistics, neuroscience, and psychology. The authors take readers for a deep dive into different underlying problems that lead to lexical access and retrieval difficulty and strategies to remediate them effectively. By addressing lexical issues from a broader view, this unique resource helps readers see the connections from different perspectives to further understand the complex issues involved in lexical learning and retrieval.