The most common and most likely answer to this crossword clue is the 6 letter word LYRICS
I've seen this crossword clue in The Guardian
L
Y
R
I
C
S
More clues leading to the result LYRICS
- Lady rabbi condemns empty words
- Cyril’s playing with words in numbers
- Words of Saint Cyril in translation
- Heartless lady upset gent, penning first of cruel words
- Scarily edit out a criminal's words
- At first loud cry is let loose for words of a song
- Words taking up a hundred and one lines, fifty on soprano
Buddy explains!

The straight part
We know that "words in numbers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case words in numbers = lyrics.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 LYRICS mean?
LYRICS noun- A lyric poem.
- (also in plural) The words of a song or other vocal music. The singular form often refers to a part of the words, whereas the plural form can refer to all of the words.
- The words to a song (or other vocal music).