H (8)
'h' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for hydrogen that I've seen before include "Lightest and most abundant of all substances" , "Light gas" , "Chemical element with atomic no. 1 in the periodic table" , "... ditto: symbol H" , "Element with atomic number 1" .)
'h' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eta that I've seen before include "Letter of Greek alphabet" , "When one is due" , "When's end of journey predicted" , "Basque separatist movement" , "Greek character?" .)