The most common and most likely answer to this crossword clue is the 4 letter word PINT
P
I
N
T
More clues leading to the result PINT
Buddy explains!

The straight part
We know that "Tiny" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tiny = pint.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 PINT mean?
PINT noun- A unit of volume, equivalent to:
- (metonym) A pint of milk.
- (metonymy) A glass of beer or cider, served by the pint.