The most common and most likely answer to this crossword clue is the 8 letter word BAPTISMS
I've seen this crossword clue in The Guardian
B
A
P
T
I
S
M
S
More clues leading to the result BAPTISMS
Buddy explains!
The straight part
We know that "Font functions" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case font functions = baptisms.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 BAPTISMS mean?
BAPTISMS noun- A Christian sacrament, by which one is received into a church and sometimes given a name, generally involving the candidate to be anointed with or submerged in water.
- A similar ceremony of initiation, purification or naming.