Clots throb, I am shortly indisposed (7)
I believe the answer is:
thrombi
'clots' is the definition.
(thrombus is a kind of clot)
'throb i am shortly indisposed' is the wordplay.
'shortly' means to remove the first letter.
'indisposed' indicates anagramming the letters.
'am' with its first letter removed is 'm'.
'throb'+'i'+'m'='throbim'
'throbim' with letters rearranged gives 'THROMBI'.
(Another definition for thrombi that I've seen is " Blood clots".)
I've seen this clue in The Telegraph.
Want a hint initially instead of a full solution?
Install my app