The most common and most likely answer to this crossword clue is the 4 letter word ATOM
I've seen this crossword clue in The Guardian
A
T
O
M
More clues leading to the result ATOM
- First of two encyclopedia volumes, perhaps, is a tiny thing
- Thirteen letters identifying a small thing
- A tiny bit a hustler
- Section of index maybe that traditionally can't be split?
- Scrap a vehicle test requiring reversing
- First half of alphabet or very small amount?
- Art form oddly seen as something minute
- Trace a revolutionary word from Robespierre?
- Very small bit of a 15?
- Tiny fragment gleaned from Nato message
Buddy explains!
The straight part
We know that "that’s very small" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case that’s very small = atom.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 ATOM mean?
ATOM noun- The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.
- (history of science) A hypothetical particle posited by Greek philosophers as an ultimate and indivisible component of matter.
- The smallest, indivisible constituent part or unit of something.
- In logical atomism, a fundamental fact that cannot be further broken down.
- The smallest medieval unit of time, equal to fifteen ninety-fourths of a second.
- A mote of dust in a sunbeam.
- A very small amount; a whit.
- (Lisp) An individual number or symbol, as opposed to a list; a scalar value.
- A non-zero member of a Boolean algebra that is not a union of any other elements. Or, a non-zero member of a Boolean lattice that has only zero below it.
- An element of a set that is not itself a set; an urelement.
- (usually capitalised as "Atom") A member of an age group division in hockey for ten- to 11-year-olds.