The most common and most likely answer to this crossword clue is the 5 letter word HUMUS
H
U
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U
S
More clues leading to the result HUMUS
- Decomposing material smells badly around University
- Soil constituent reeks, overwhelming university
- Decomposing matter emits awful smell around university
- Rotting material stinks outside entrance to urinal
- Organic stuff brings nasty smell to you and me
- Smell American appetiser
- Rotten smell American leaves after decomposing
- We in Delhi get American garden matter
Buddy explains!

The straight part
We know that "garden matter" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case garden matter = humus.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 HUMUS mean?
HUMUS noun- A large group of natural organic compounds, found in the soil, formed from the chemical and biological decomposition of plant and animal residues and from the synthetic activity of microorganisms
- A Levantine Arab dip made of chickpea paste with various additions, such as olive oil, fresh garlic, lemon juice, and tahini, often eaten with pitta bread, or as a meze. It is mostly eaten in the Levant.