What is this?

[AustinPowers]

HIJKLMNO

(5 Letters)

?

 

[LittleShip]

Water H2O

Tom

 

[sarabande]

dihydrogen monoxide

 

[RIN]

HIJKLMNO

(5 Letters)

?

I'm not playing until the Fish thread is answered

 

[AustinPowers]

dihydrogen monoxide

Sorry Sara, nice try but slightly more than 5 letters there!

 

[colingr]

Little Ship already has it.

Bit like the

Overloaded Postman clossword clue

 

[AustinPowers]

Hehe, how many letters?

 

[colingr]

Too many to count

 

[stownsend]

H to O, ie H2O, therefore water !!