Learn Farsi: ما برای دفع این موش‌ها از تله ضد جونده استفاده می‌کنیم. - We use an anti-rodent trap to repel these mice.

The word ضد (zedd) means "anti" or "against" and links to a noun with an ezafe to form a compound adjective. Here, it links to جونده (javande - rodent) to mean "anti-rodent". Because this whole phrase acts as a single adjective describing تله (tale - trap), you need another ezafe to connect the noun to its adjective, pronounced as "tale-ye zedd-e javande".

Where does the word جونده (javande) come from?

It is formed from the present stem of the verb جویدن (javidan - to chew or gnaw), which is جو (jav-), plus the suffix ـَنده (-ande). This suffix creates a noun or adjective for the "doer" of the action, so جونده literally means "chewer" or "gnawer", which is the standard Farsi word for "rodent".

We are repelling multiple mice (این موش‌ها). Why isn't جونده plural?

In Farsi, when you use ضد (zedd) to create a category-based compound adjective, the noun attached to it generally stays singular. Just like in English we say "anti-rodent" (not "anti-rodents"), Farsi uses the singular جونده to refer to the general category of the pest.

Why is there an از (az) before the trap?

This is required by the verb. The Farsi equivalent of "to use" is the compound verb استفاده کردن (estefade kardan), which conceptually means "to make use". It always requires the preposition از (from) to introduce the object being used.