Congratulatory /kənˈɡraCHələtôrē/ adj.

Definition:  Congratulatory describes wishing someone the best after they have completed an achievement or have been successful at working towards something. People have been known to send messages to the Queen wishing her congratulations on claiming her throne.

Etymology: Congratulatory originates from the Latin word congratulari in the 1520s, and it means joy. People use this word in its plural form, which is congratulations. In the 1540s, the word congratulate was a verb with con meaning together. The whole word means to address with pleasure. 

The word started out as congratulari in Latin. The spelling changed to congratulato and is still Latin, but it changed again to become an English word, congratulate.

In a Sentence

Two best friends gave each other a congratulatory hug after completing their masters in child psychology.

A woman gave her husband a congratulatory hug and kiss after finding out that he had landed his dream job.

Due to the pandemic, some people feel uncomfortable giving each other congratulatory hugs and handshakes, so they give each other congratulatory air fives.

Synonyms 

Flattering, Celebratory, Complimentary

Antonyms 

Inappreciative, Hypercritical, Belittle