The most common and most likely answer to this crossword clue is the 2 plus 5 letter word BY HEART
I've seen this crossword clue in The Guardian
B
Y
H
E
A
R
T
More clues leading to the result BY HEART
- Memorised last of story in the bar, drunk
- From memory, boy’s gutted, given red card
- Recite Farewell, My Lovely from memory
- Past: pluck from memory
- Close to centre, from memory
- The way to learn things is through courage
- Pat‘s husband snared in extra cunning
- Not after compassion off Pat
- Describing a form of learning in book before period covering hard topics initially
Buddy explains!
The straight part
We know that "from memory" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case from memory = by heart.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.