apalabrar

To agree on something verbally, sealing a deal or arrangement with one's word before (or instead of) putting it in writing — apalabrar un precio, apalabrar una cita. Common in informal business dealings and everyday arrangements across the Spanish-speaking world.

• Apalabramos el alquiler del piso antes de firmar el contrato. — We verbally agreed on the apartment rent before signing the contract.
• Ya tenían apalabrada la venta del coche. — They had already verbally agreed on the sale of the car.
• Apalabraron una reunión para la próxima semana. — They arranged a meeting for next week, verbally.

Treating an apalabrado agreement as legally binding the way a signed contract is — the whole point of the word is that it's a verbal, informal commitment, which culturally carries weight but not the same legal force.