1. Belonging to them

Sounds like: there's

Encyclopedia: Theirs

• Medicaid
• Medicaid funds
• medical
• Costa Rican colón
• Costa Rican monetary unit
• costal
• costal cartilage
• costal groove
• costalgia
• Costanoan
• costard
• costate
• coster
• costermonger
• costia
• Costia necatrix
• costiasis
• costing
• costive
• costless
• costliness
• costly
• costmary
• costoaxillary vein
• costochondritis