Semen /ʂemen/ or Xemen /ʃemen/ is a medieval Basque given name of the Vasconic area. It is based on the Basque root seme < senbe 'son' as found in the ancient Aquitanian name Sembetten, attested form "sehi" as 'child', hypothetical ancient root *seni (cf. Koldo Mitxelena and modern form "senide" = 'brother or sister', 'relative'). The explanation by the Biblical name Šim’ōn (Simon) is less convincing.^{[citation needed]} Some think the name may be a corruption of the later part of the Latin name Ma-ximinus, as there are late Classic records that various individuals with this name were becoming very active as officials and residents in upper Hispania near the Pyrenees and Tarraconensis during the last century of the Western Roman Empire, and perhaps into the period of transition from imperial province to independent Kingdom during Visigothic rule.^{[citation needed]}

Additionally, the voiceless retroflex fricative variant of the name Semen is a homograph of the English word for semen, a bodily fluid secreted by the sexual organs of male or hermaphroditic animals.

A "Seguin" was attested in Frankish chronicles when referring to the Count of Bordeaux and Duke of Vasconia (778, 814 and 816). The name is also recorded as Sihiminus, perhaps a rendering of Ximinus. He may have been a local Basque whose family later fled south over the Pyrenees and helped Enneco Arista take over in Pamplona.^{[citation needed]}

Arab sources in Al-Andalus report in 778 a "Jimeno, the strong", calling him "Mothmin al-Akra". He was a Basque or Hispanic magnate in the upper Ebro territories within the later independent principality of Navarre. This person was possibly related to others near Pamplona in local opposition to both the invading Franks under Charlemagne and the new ruler of the Islamic Iberian realm, Abd al-Rahman I.

Other than these early medieval examples, it is widely known on both sides of the Pyrenees in the following forms:

• Semyon or Semeno fem. Semena
• Semero fem. Semera
• Scemeno (in Villabáscones)
• Xemen or Xemeno fem. Xemena
• Ximeno or Jimeno fem. Ximena or Jimena (French Chimène)

By adjunction of the patronymic suffixes -ez or -es, it produces the Iberian patronyms:

• Portuguese: Ximenes [ʃiˈmeneʃ]
• Spanish: Ximénez, Giménez, Jiménez [xiˈmeneθ]

Semen is also a transliteration of the Ukrainian given name Семе́н and an alternate transliteration of the Russian given name Семё́н (more often transliterated as Semyon); both words (along with an etymologically cognate Ukrainian name Си́мон—Symon and an etymologically cognate Russian name Си́мон—Simon) derive from a biblical name Simeon/Symeon. Notable persons with that name include:

• Semyon Altman (born 1946), Ukrainian football coach
• Semyon Bogdanov (1894–1960), Soviet Marshal of the Army
• Semyon L. Frank (1877–1950), religious philosopher
• Semyon Hulak-Artemovsky (1813–1873), Ukrainian opera composer, singer, actor, and dramatist
• Semyon Kirsanov (1906–1972), Ukrainian poet in Russia
• Semyon Korsakov (1787–1853 OS), inventor who was involved with an early version of information technology
• Semyon Paliy (c. 1645–1710), Ukrainian Cossack polkovnyk (colonel)
• Semyon Pavlichenko (born 1991), Russian luger
• Semyon Semenchenko (born 1974), Ukrainian politician, founder and former commander of Donbas Battalion
• Semyon Tymoshenko (1895–1970), Soviet military commander
• Semyon Zhavoronkov (1899–1967), Soviet Marshal of the Air Force
• Semyon Zhivago (1807–1863), Russian painter

• Basque Onomastics of the Eighth to Sixteenth Centuries