Maiden Queen's captured by period author (7)
I believe the answer is:
emerson
'author' is the definition.
(US author Ralph Waldo Emerson, 1803-1882)
'maiden queen's captured by period' is the wordplay.
'maiden' becomes 'm' (cricket abbreviation).
'queen's' becomes 'ers' (abbreviation for Elizabeth Regina).
'captured by' means one lot of letters goes inside another.
'period' becomes 'eon' (eon is a kind of period).
'm'+'ers'='mers'
'mers' inserted inside 'eon' is 'EMERSON'.
(Other definitions for emerson that I've seen before include "American writer, 1803-82" , "Ralph Waldo . . ., 19th century American philosopher and poet" , "Individualist" , "he could write!" , "Ralph Waldo --, US author" .)