This is the 4467th most frequent Russian word.
вооружениями
"Вооружениями" means "armaments" or "weapons."
The noun 'вооружениями' is used here in the instrumental plural form to indicate the means (armaments) concerning the agreement.
Государства договорились о сокращении вооружений.
The states have agreed on the reduction of armaments.
'Вооружениями' is used in the instrumental plural form to describe the theme of the exhibition.
Выставка посвящена современным вооружениям и технологиям их производства.
The exhibition is dedicated to modern armaments and their production technologies.
In this sentence, 'вооружениями' helps identify the object of the research activity in its instrumental plural form.