What does fraternal mean?
Fraternal is an adjective describing anything relating to brothers or evoking the qualities of a brotherly bond — loyalty, warmth, and mutual support. Its uses fall into three main areas: kinship (the relationship between brothers), fellowship (the camaraderie found in lodges, societies, unions, and other fraternal organizations), and biology, where 'fraternal twins' refers to non-identical twins who develop from two separate fertilized eggs. Derived from Latin roots meaning 'brotherly', the word carries a friendly, cooperative connotation rather than an aggressive or exclusive one. It appears frequently in institutional contexts — fraternal orders, benefit societies, and professional associations — where it signals solidarity among members. Because of its firm association with twin types in popular science, many people first encounter the word through genetics, even though its older and broader meaning concerns human brotherhood in all its forms. It remains common in both British and American usage.
adjectiveRelating to brothers, or characteristic of the bond between brothers; also used more broadly to describe a warm, brotherly fellowship among people who are not related.
- Of, relating to, or characteristic of brothers or a brotherly relationship.
- Showing warm fellowship and mutual support, as in clubs, lodges, and societies (a 'fraternal' spirit).
- In biology: describing non-identical twins developed from two separately fertilized eggs.
"The twins shared a fraternal bond that survived decades of living on different continents."
"He felt a fraternal affection for his old army comrades that ran deeper than mere friendship."
"The fraternal lodge raised money for members' families in times of hardship."
Fraternal twins can look nothing alike — or be as similar as any two siblings — because they start life as two separate fertilized eggs.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of fraternal
Fraternal derives from Latin frater ('brother'), via the Late Latin adjective fraternalis, meaning 'of or belonging to a brother'. The word entered English in the early modern period, appearing in English writing by the early seventeenth century. The same Latin root gives rise to fraternity, fraternization, and confrère, all of which express brotherhood in religious, social, or professional settings.
Related word forms
How fraternal is actually used
The word carries warm, positive connotations of loyalty and solidarity, and is often used formally in the names of benevolent societies and trade organizations. In everyday language it is strongly associated with 'fraternal twins', which makes it one of the few dictionary words with a routine scientific application. The related noun 'fraternity' is used for actual organizations.
Easily confused with fraternal
In twin terminology, 'fraternal' describes twins from two separate eggs who are no more genetically alike than ordinary siblings, whereas 'identical' describes twins from a single fertilized egg with matching genes.