Something described as hostile is definitely not friendly, peaceful, or helpful. For instance, in business, a hostile takeover is an aggressive move to seize control of a company against the wishes of its current leadership — not friendly! In contrast, a hostel is an inexpensive lodging facility that welcomes weary travelers, providing a place to rest, refresh, and often socialize in a friendly atmosphere.
The Latin root of the word hostile is hostis — meaning "an enemy." Hostile can be used to describe an unfriendly nation, group, remark, action, environment, or even a harsh climate. Used as a noun, hostiles are the military troops of an enemy in times of war. Here are a few examples of the correct uses of hostile:
Faced with such hurtful and hostile interactions, she turned to her female friends to keep her strong. (Votes for Women!)
Both specialists were heavy-equipment operators doing a tough job in a hostile region. (The New York Times)
"So, son, can you decode this thing? So far, our top cryptographers, all of whom are assembled here, haven't been able to. What are the hostiles' intentions?" (The Smartest Kid in the Universe)
The word hostel comes from the Medieval Latin hospitale, meaning "inn, or large house." Historically, if a college student took a year to travel abroad, chances are they stayed in at least one youth hostel, where they likely shared accommodations with other students traveling solo. Supervised, inexpensive, and often offering food, a hostel fit perfectly into a traveling student's limited budget. Hostels are still popular with students, backpackers, bikers, and other adventurers on a budget. Most European cities have at least one hostel, and there are now hostels in many places around the world. Check out these examples of hostel:
"No, sweetie, a hostel is an affordable place to stay when you travel." (Marcus Vega Doesn't Speak Spanish)
For 60 years from 1945 the castle was a youth hostel, but during World War Two it had served as a sanctuary for members of the Norwegian royal family after Nazi Germany's invasion of Norway. (BBC)
A hostel is much like a hotel, and if you remove the s from the word hostel, you get the word hotel. Remember that hostels offer hospitality — providing generous, friendly services to guests — while someone or something that is hostile offers ill will and aggression — anything but hospitality.