proponent russian

• сторо́нник

  supporter, adherent, follower, backer

  advocate, proponent, believer (in an idea), champion

• урбани́ст

  urbanist, urban planner, urban designer

  urbanist, advocate of city living, proponent of urbanism

• славянофи́лка

  Slavophile (female), a female proponent of Slavophilism

Examples

• Сторонники нептунизма считали воду главной силой природы.

  The proponents of Neptunism believed that water was the main force of nature.