Mervyn Is A Boys Name Of Old Welsh Origin. Meaning "sea Friend," This Name Has The Perfect Amount Of Whimsy For Any Little Dreamer, And Can Encourage Them To Treat The World Around Them With Love And Compassion. Its An Alternative Spelling Of Marvin, But Sounds Enough Like Merlin To Have A Certain Magical Feel Thats Sure To Go Down A Storm. This Name Goes Back Centuries, With A 9th-century King Of Gwynedd Being Called Mervyn, Spelled Merfyn Frych.