1. the absence or deficiency of specialized knowledge, skill, or experience in a particular field or domain
The project failed due to a lack of expertise in project management.
O projeto fracassou devido à falta de expertise em gestão de projetos.
2. insufficient professional competence or technical proficiency required to perform a task effectively
His lack of expertise in coding made it difficult for him to complete the assignment.
A sua falta de expertise em codificação dificultou a conclusão da tarefa.