waffenfähigem
Waffenfähigem is the dative singular form of the German adjective *waffenfähig*, meaning “armed” or “capable of being armed”. The word is derived from *Waffe* (weapon) and the suffix *‑fähig* (capable). In ordinary speech the adjective appears in attributive position before a noun, e.g. *waffenfähiger Dienstbesatzung*. In the dative case the masculine and neuter adjective endings are *‑em*, so *waffenfähigem* would be used with a masculine or neuter noun in a dative construction, such as *mit einem waffenfähigem Gerät*.
In legal and security contexts *waffenfähigem* and its related noun forms (*Waffenfähigkeit*, *waffenfähiges Gerät*, *waffenfähige Vorrichtung*)
While *waffenfähigem* is a textbook case of German adjective morphology, it is rarely used in everyday conversation.