основополагающий angolul

fundamental▼(pertaining to the foundation or basis; serving for the foundation)
adjective
[UK: ˌfʌn.də.ˈmen.tl̩] [US: ˌfʌn.də.ˈmen.tl̩]

seminal▼(highly influential)
adjective
[UK: ˈse.mɪn.l̩] [US: ˈse.mən.l̩]