Short answer: land given out by the king was commonly referred to as the king’s demesne or royal demesne, and more broadly as a fief or fee granted to a lord in exchange for service. Details

• Royal demesne: land held directly by the Crown, or land kept for the king’s own use, which could be granted out to tenants-in-chief or nobles while the king retained ultimate ownership. This term appears in discussions of medieval landholding and the Domesday Book era. [royal demesne]
• Demesne: in general feudal terms, the portion of the lord’s land that was retained for his own use rather than leased to others; the king’s demesne specifically refers to lands under royal control. [demesne]
• Fief (fee): a grant of land by a lord (often the king) to a vassal in return for military or other service; the lord retained ownership while the vassal held it in feudal tenure. [fief]
• Tenant-in-chief: a noble who held land directly from the king and thereby acted as a primary intermediary in the allocation of land to sub-tenants. [tenant-in-chief]

If you want, I can tailor the explanation to a specific region or time period (e.g., early medieval England after 1066, or the broader European feudal context) and outline how terminology evolved over time.