pre-noun adjectival
main; chief; principal; important
Pre-noun adjectival (rentaishi) used to modify a noun, indicating the most important or primary thing among a group. Often used in formal or explanatory contexts.
See also: 主 (おも)
主な理由は経済的なものです。
The main reason is economic.
この町の主な産業は観光です。
The main industry of this town is tourism.
Adverbial form meaning 'mainly' or 'mostly', while 主な is a pre-noun adjectival meaning 'main'.
Also a pre-noun adjectival meaning 'major' or 'principal', but more formal and often used in written language or official contexts.
Derived from the adjective 主 (おも, 'main, chief') with the attributive ending な, forming a pre-noun adjectival.