The most common and most likely answer to this crossword clue is the 6 letter word GUSHER
I've seen this crossword clue in The Daily Telegraph
G
U
S
H
E
R
More clues leading to the result GUSHER
- Ancient teacher, after essential bit of surgery, gets well
- Good wedding attendant: well?
- Face of girl guide, a sentimental sort?
- Good American, that woman who oozes enthusiasm?
- Well woman visits teacher, missing a university
- Initially, girl guide is well
- Grand guide, one exuding enthusiasm
- Good court official is well
- At opening of Golconda, escort is an excessive talker
- Endless blast with her dream of an oilman
Buddy explains!

The straight part
We know that "one exuding enthusiasm" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one exuding enthusiasm = gusher.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 GUSHER mean?
GUSHER noun- One who gushes (makes an excessive display of enthusiasm, praise, or sentiment).
- An oil well that has a natural flow and so requires no pumping.