Sitter/ˈsɪtər/ Definition 1 of 5Pro Tip 1/2Temporary Caregiver A sitter is someone who temporarily takes care of children, not a permanent guardian. We’re hiring a sitter for just the weekend. Pro Tip 2/2Short-term Job 'Sitter' often implies a casual or part-time job rather than a career. My neighbor is a sitter; she helps us out sometimes.