Mike tucking into triple shake (7)
I believe the answer is:
tremble
'shake' is the definition.
(I know that tremble is a kind of shake)
'mike tucking into triple' is the wordplay.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'tucking into' is an insertion indicator.
'triple' becomes 'treble' (synonyms).
'm' going into 'treble' is 'TREMBLE'.
(Other definitions for tremble that I've seen before include "Shake involuntarily" , "Shake - quiver" , "Betray nerves" , "Shake with fear or excitement" , "quail" .)