The most common and most likely answer to this crossword clue is the 6 letter word LIQUID
L
I
Q
U
I
D
More clues leading to the result LIQUID
- One's put in two pounds for 17?
- Fifty-one pounds held in cash
- £51 in cash
- Parisian who probes top lunch where food’s lacking
- Madame’s who’s filled bottomless pool, with this?
- £51 solution?
- Fifty-one pounds ready to spend
- Do such assets flow and spill out?
- One’s money, after loss, is disposable
- 51 pounds — readlily redeemable
Buddy explains!

The straight part
We know that "this?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this? = liquid.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 LIQUID mean?
LIQUID noun- A substance that is flowing, and keeping no shape, such as water; a substance of which the molecules, while not tending to separate from one another like those of a gas, readily change their relative position, and which therefore retains no definite shape, except that determined by the containing receptacle; an inelastic fluid.
- A class of consonant sounds that includes l and r.
- Flowing freely like water; fluid; not solid and not gaseous; composed of particles that move freely among each other on the slightest pressure.
- (of an asset) Easily sold or disposed of without losing value.
- (of a market) Having sufficient trading activity to make buying or selling easy.
- Flowing or sounding smoothly or without abrupt transitions or harsh tones.
- Pronounced without any jar or harshness; smooth.
- Fluid and transparent.