This is the 10011th most frequent Russian word.
армейского
"Army" or "military" (adjective form).
The word 'армейского' is used here as a possessive adjective derived from 'армейский', meaning 'army-related', modifying 'ботинка' (boot).
Солдат носил армейского ботинка.
The soldier wore an army boot.
The word 'армейского' is employed as an adjective to describe 'карте' (map), indicating its relation to the army.
Мы изучали топографию на армейского карте.
We studied topography using an army map.
Here, 'армейского' describes 'стандарту' (standard), showing its association with military or army-specific standards.