A very well put together list Boy names !

Japeth is a masculine name that appears to be a variant spelling of Japheth, who in biblical tradition was one of Noah's three sons in the Book of Genesis. The name is of Hebrew origin and is thought to mean 'enlarge' or 'expand,' with some interpretations suggesting 'beautiful' or 'may he have space.' This alternate spelling is much less common than the traditional Japheth. The name carries significant religious and historical weight in Judeo-Christian traditions, where Japheth is considered an ancestor of various European and Asian peoples. While never extremely popular in modern times, the name has maintained a steady presence among those who appreciate biblical names or are looking for something with ancient roots and spiritual significance.

Sinclaire is a sophisticated masculine name that originated as a surname derived from the Norman French 'Saint Clair,' meaning 'holy light' or referring to someone from the town of Saint-Clair in France. This spelling variation, with the added 'e' at the end, gives the name a refined, elegant quality. While traditionally more common as a surname, Sinclaire has occasionally been used as a first name for boys, offering a distinguished alternative to more common names. It carries associations with clarity and illumination through its etymological roots. The name has a certain aristocratic flair and literary quality that might appeal to parents seeking something uncommon yet classic-sounding for their son.

Saige as a masculine name represents a gender-crossing usage of what has traditionally been more common as a feminine name in recent decades. Derived from the herb sage (Salvia), the name carries connotations of wisdom and knowledge—sage has long been a term for a wise person. The alternative spelling with 'i' gives it a contemporary touch while maintaining the connection to its meaningful roots. While Saige has gained moderate popularity as a girl's name in the United States since the 2000s, its use for boys remains relatively uncommon, making it a distinctive choice. The name's short, strong sound works well for any gender, offering a modern unisex option with ancient wisdom associations.

Casimer is a masculine name of Polish origin, representing an Anglicized variant of Kazimierz (Casimir). The name derives from Slavic elements meaning 'destroyer of peace' or 'announcer of peace,' though the latter interpretation is more commonly embraced. It gained prominence through several Polish kings and saints named Casimir, particularly St. Casimir, patron saint of Poland and Lithuania. While never extremely common in English-speaking countries, Casimer enjoyed modest usage in Polish-American communities throughout the 20th century. The name carries an air of aristocratic heritage and Eastern European character. Its traditional roots appeal to parents seeking names with historical depth and cultural significance. Casimer offers its bearers a distinguished name with royal connections while remaining distinctive in most contemporary settings.