Convivial Meaning: Friendly

Synonyms: Affable, cordial, amiable, etc.
Antonyms: Unfriendly, unsociable, etc.

Example: 
1) The festive atmosphere was convivial.
2) A letter is more convivial than an online post.
3) After yoga, my mood is very convivial.
4) If you are not convivial then you must not host a party.