noun, noun which may take the genitive case particle 'no'
unitary; single element; single source or principle
Used mostly in formal or abstract compounds and modifiers for something treated as one unified element, source, principle, or system.
顧客情報を一元管理する仕組みを作った。
We created a system to manage customer information in one centralized place.
この理論は社会を一元の原理で説明しようとする。
This theory tries to explain society by a single principle.
noun
one era; single era name
Rare historical use, most familiar in the phrase 一世一元, referring to using one era name for one reign or sovereign.
明治以後、日本では一世一元の制が採られた。
From the Meiji period onward, Japan adopted the system of one era name per reign.
noun
one unknown; one variable
Mathematical term used in compounds such as 一元方程式 and 一元一次方程式, meaning that an equation has one unknown quantity.
授業で一元一次方程式を解いた。
We solved linear equations in one unknown in class.