The most common and most likely answer to this crossword clue is the 7 letter word GLADDEN
I've seen this crossword clue in The Daily Telegraph
G
L
A
D
D
E
N
More clues leading to the result GLADDEN
- Info about stableman ultimately bound to cheer
- News about youth ultimately designed to cheer
- Make merry to combine in mountain valley
- Info about youth meeting daughter, please
- A theologian in valley brings cheer
- Good boy, study please
- Valley welcoming a theologian to provide cheer
- Raise the spirits of a cleric in depression
- Please increase admission to the valley
- Information involving son and daughter makes one cheer
Buddy explains!

The straight part
We know that "cheer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cheer = gladden.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GLADDEN mean?
GLADDEN verb- To cause (something) to become more glad.
- To become more glad in one's disposition.