Priest coming to holy mount, cutting bit of speech short (7)
I believe the answer is:
elision
'cutting bit of speech short' is the definition.
'elision' can be an answer for 'cutting' (thesaurus). I'm not certain of the 'bit of speech short' bit.
'priest coming to holy mount' is the wordplay.
'priest' becomes 'eli' (biblical figure).
'coming to' means one lot of letters go next to another.
'holy mount' becomes 'sion' (I can't explain this - if you can you should believe this answer much more).
'eli'+'sion'='ELISION'
Can you help me to learn more?
(Other definitions for elision that I've seen before include "Omission of a sound in speech" , "Omission (of a syllable)" , "Dropping a letter" , "Dropping of vowel" , "Omission of syllables in speech" .)