His Excellency’s false accounts about 100 spirals (7)
I believe the answer is:
helices
'spirals' is the definition.
('helix' can be a synonym of 'spiral')
'his excellency's false accounts about 100' is the wordplay.
'his excellency' becomes 'he'.
'false accounts' becomes 'lies' (I can't justify this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'l00' becomes 'C' (roman numeral).
'lies' enclosing 'c' is 'lices'.
'he'+'lices'='HELICES'
Can you help me to learn more?
(Other definitions for helices that I've seen before include "spirals downwards, perhaps" , "curves" , "twisting forms" .)