The most common and most likely answer to this crossword clue is the 8 letter word APPEARED
I've seen this crossword clue in The Daily Telegraph
A
P
P
E
A
R
E
D
Buddy explains!
The straight part
We know that "entered" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case entered = appeared.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 APPEARED mean?
APPEARED verb- To come or be in sight; to be in view; to become visible.
- To come before the public.
- To stand in presence of some authority, tribunal, or superior person, to answer a charge, plead a cause, etc.; to present oneself as a party or advocate before a court, or as a person to be tried.
- To become visible to the apprehension of the mind; to be known as a subject of observation or comprehension, or as a thing proved; to be obvious or manifest.
- To seem; to have a certain semblance; to look.
- To bring into view.