The most common and most likely answer to this crossword clue is the 6 letter word FAMISH
I've seen this crossword clue in Financial Times
F
A
M
I
S
H
More clues leading to the result FAMISH
- Go very hungry dividing food around a million
- Frequency with which sect members go hungry
- Make weak swimmers admit any misgivings at the outset
- Suffer great hunger in the morning, wanting eg sardines brought round
- Frequency with which US sect starve
- What you shouldn’t do with a thousand fish around
- Deprive of cheer fellow leading US sect
- Starve following religious sect
- A thousand must tuck in to seafood or starve
- Hunger in the morning when there’s possible food around?
Buddy explains!

The straight part
We know that "Make weak" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case make weak = famish.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 FAMISH mean?
FAMISH verb- To starve (to death); to kill or destroy with hunger.
- To exhaust the strength or endurance of, by hunger; to distress with hunger.
- To kill, or to cause to suffer extremity, by deprivation or denial of anything necessary.
- To force or constrain by famine.
- To die of hunger; to starve.
- To suffer extreme hunger or thirst, so as to be exhausted in strength, or to come near to perish.
- To suffer extremity from deprivation of anything essential or necessary.