1.  roundhead(n = noun.person) - a brachycephalic person;
is a kind of individual, mortal, person, somebody, someone, soul

2.  roundhead(n = noun.person) - a supporter of parliament and Oliver Cromwell during the English Civil War;
is a kind of admirer, booster, champion, friend, protagonist, supporter

   A nickname for a Puritan. See Roundheads, the, in the Dictionary of Noted Names in Fiction. Toone. [1913 Webster]

roundhead, n. hist. a member of the Parliamentary party in the English Civil War.

Etymology:
f. their custom of wearing the hair cut short