This is the 8111th most frequent Russian word.
ларсон
"Ларсон" is a transliteration of "Larson," typically used as a surname and does not have a specific meaning in Russian.
Here, 'Ларсон' ('Larson') is used as a proper noun to indicate a specific person's surname.
Ларсон был известным актёром в Голливуде.
Larson was a famous actor in Hollywood.
In this sentence, 'Ларсона' ('Larson') is used in the genitive case to denote possession, indicating that the cars belong to Larson.
Все машины Ларсона выглядели отлично.
All of Larson's cars looked excellent.
Here, 'Ларсону' ('Larson') is in the dative case to indicate the recipient of the action, meaning the letter was addressed to Larson.