Yassen is a masculine given name of Slavic provenance, derived from the Bulgarian term jasen—literally “ash tree” and by extension “clarity” or “brightness.” Its phonetic profile remains stable across language boundaries, rendered as YAH-sen (Bulgarian /ˈjasɛn/, English /ˈjɑːsən/), which underscores its technical consistency in both native and Anglo-American usage. An analysis of United States Social Security Administration data from 2005 through 2020 shows that Yassen has appeared intermittently in the lower quartile of the top 1,000 male names, with annual occurrences ranging from five to sixteen and ranks oscillating between 869 and 923. These metrics reflect the name’s status as a distinctive yet moderately integrated choice within contemporary naming conventions, offering parents a designation that marries historical Slavonic resonance with dependable phonological form.