A type of motor delay characterized by a delay in acquiring the ability to control the large muscles of the body for walking, running, sitting, and crawling. The phenotype is Delayed gross motor development (HP_0002194). Also known as: Delayed attainment of gross motor milestones, Delayed attainment of gross motor skills, Delayed development of gross motor milestones, Delayed development of gross motor skills, Delayed gross motor milestones, Delayed gross motor skills, Delayed motor skills, Developmental delay, gross motor.