A seller or vendor — the person or party selling goods, real estate, or services; the selling side in a transaction.
売り主と買い主で契約条件をすり合わせた。
The seller and the buyer adjusted the contract terms.
売り主が物件の不具合を事前に知らせていなかった。
The seller had not informed about the defects in the property beforehand.
売り主の連絡先は契約書に明記されている。
The seller's contact information is stated in the contract.