The most common and most likely answer to this crossword clue is the 4 letter word MITE
I've seen this crossword clue in Independent
M
I
T
E
More clues leading to the result MITE
- Modest offering from overseas university: English
- Small creature’s power spoken about
- Don’t start to hit small child
- A widow’s gift could possibly — so to speak
- Tiny child’s modest contribution
- Small amount in moieties oddly
- Before leaving reclusive sort makes widow’s contribution
- Biblical widow had more than one small child
- University education kicking off a little bit
- Scrap force, we hear
Buddy explains!

The straight part
We know that "widow’s contribution" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case widow’s contribution = mite.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 MITE mean?
MITE noun- Any of many minute arachnids which, along with the ticks, comprise subclass Acarina (aka Acari).
- A small coin formerly circulated in England, rated at about a third of a farthing.
- A lepton, a small coin used in Palestine in the time of Christ.
- A small weight; one twentieth of a grain.
- (sometimes used adverbially) Anything very small; a minute object; a very little quantity or particle
- (often used affectionately) A small or naughty person, or one you take pity on; rascal