The most common and most likely answer to this crossword clue is the 7 letter word LEANEST
I've seen this crossword clue in The Daily Telegraph
L
E
A
N
E
S
T
More clues leading to the result LEANEST
- Very thin ale sent for replacement
- Least productive 20th-century director is French
- Most unproductive place for meadowlark’s eggs?
- Home behind field that’s most unproductive
- Thinnest and smallest eating nectarine’s rind
- Most meagre home for bird on meadow
- Meadow pipit’s home with the most slender dimensions
- Superlatively poor way to cross English street
- Nibble ends in smallest getting most emaciated
- Scantiest minimum worn around Tyneside area
Buddy explains!

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 LEANEST mean?
LEANEST verb- To incline, deviate, or bend, from a vertical position; to be in a position thus inclining or deviating.
- To incline in opinion or desire; to conform in conduct; often with to, toward, etc.
- Followed by against, on, or upon: to rest or rely, for support, comfort, etc.
- To hang outwards.
- To press against.
- To thin out (a fuel-air mixture): to reduce the fuel flow into the mixture so that there is more air or oxygen.
- (of a person or animal) Slim; not fleshy.
- (of meat) Having little fat.
- Having little extra or little to spare; scanty; meagre.
- Having a low proportion or concentration of a desired substance or ingredient.
- Of a character which prevents the compositor from earning the usual wages; opposed to fat.
- Efficient, economic, frugal, agile, slimmed-down; pertaining to the modern industrial principles of "lean manufacturing"
- To conceal.