This is the 3139th most frequent Russian word.
ледников
The Russian word "ледников" means "of glaciers" or "glacial" (possessive/plural form).
Here, 'ледниками' is in instrumental plural, denoting 'by glaciers', referring to natural ice formations.
Величественные горы окружены ледниками.
The majestic mountains are surrounded by glaciers.
In this sentence, 'ледников' is in genitive plural, indicating possession or origin pertaining to glaciers.
Эксперты изучают таяние ледников.
Experts are studying the melting of glaciers.
Here, 'ледников' again is in genitive plural, showing descriptive relation as part of a proper name.