The most common and most likely answer to this crossword clue is the 5 letter word FORMS
I've seen this crossword clue in The Daily Telegraph
F
O
R
M
S
Buddy explains!
The straight part
We know that "Develops/classes" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case develops/classes = forms.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 FORMS mean?
FORMS noun- (heading, physical) To do with shape.
- (social) To do with structure or procedure.
- A blank document or template to be filled in by the user.
- A specimen document to be copied or imitated.
- Level of performance.
- (grammar) A grouping of words which maintain grammatical context in different usages; the particular shape or structure of a word or part of speech.
- The den or home of a hare.
- A window or dialogue box.
- An infraspecific rank.
- The type or other matter from which an impression is to be taken, arranged and secured in a chase.
- A quantic.
- (fitness) A specific way of performing a movement.
- To assume (a certain shape or visible structure).
- To give (a shape or visible structure) to a thing or person.
- To take shape.
- To put together or bring into being; assemble.
- To create (a word) by inflection or derivation.
- To constitute, to compose, to make up.
- To mould or model by instruction or discipline.
- To provide (a hare) with a form.
- To treat (plates) to prepare them for introduction into a storage battery, causing one plate to be composed more or less of spongy lead, and the other of lead peroxide. This was formerly done by repeated slow alternations of the charging current, but later the plates or grids were coated or filled, one with a paste of red lead and the other with litharge, introduced into the cell, and formed by a direct charging current.