Wordnet 3.0
ADJECTIVE (2)
1.
shaped in the form of the black trefoil or clover leaf on some playing cards;
2.
shaped in the form of a club that is larger at one end;
The Collaborative International Dictionary of English v.0.48:
Club-shaped \Club"-shaped\, a.
Enlarged gradually at the end, as the antenn[ae] of certain
insects.
[1913 Webster]
WordNet (r) 3.0 (2006):
club-shaped
adj 1: shaped in the form of the black trefoil or clover leaf on
some playing cards
2: shaped in the form of a club that is larger at one end