It's a verb, and it can be used in various contexts, including:
* To save someone from danger: "ער האָט אראַטווען דעם קינד פון די פייַער" (Er hot aravevn dem kind fun di fayer) - He rescued the child from the fire.
* To save something from loss: "זיי האָבן אראַטווען די ספרים פון די פלאַם" (Zey hobn aravevn di s'forim fun di flam) - They saved the books from the flames.
* To redeem something: "ער האָט אראַטווען זיין נאָמען פון די שמוץ" (Er hot aravevn zayn nomen fun di shmutz) - He redeemed his name from the disgrace.
The word is derived from the Hebrew verb "להַצִּיל" (latzil), which also means "to rescue."