Enmity is a formal word that refers to a very deep unfriendly feeling, such as hatred or ill will, that is often felt mutually.

// Having to collaborate on the project only increased the bitter enmity between the two coworkers, who had never gotten along.

Rationale refers to an explanation or reason for something said or done. It is often used with for, behind, or of.

// City council members who oppose the zoning change should be ready to explain their rationale for voting against it.

// She’s explained the rationale behind her early retirement.

Jovial describes people as well as moods, attitudes, etc., that are cheerful and jolly. 

// The audience was in a jovial mood as the headlining comedian walked onto the stage.

a lively Polish dance with a moderately quick triple meter

Perpetuity refers to a state of continuing forever or for a very long time.

// The property will be passed on from generation to generation in perpetuity.  

To flummox someone is to confuse or perplex them. // The actor was easily flummoxed by last-minute changes to the script.

Zoomorphic describes things that have the form of an animal.

// The local bakery is famous for its wide variety of zoomorphic treats, from “hedgehog” dinner rolls to delicate, swan-shaped pastries.

The term griot refers to any of a class of musician-entertainers of western Africa whose performances include tribal histories and genealogies. The term is also used broadly to refer to a storyteller.

// Tracing her family lineage back to West African griots inspired the singer to focus on storytelling through her music.

anything of immense size and power