Wordnet 3.0
NOUN (1)
1.
a Chinese puzzle consisting of a square divided into seven pieces that must be arranged to match particular designs;
The Collaborative International Dictionary of English v.0.48:
Tangram \Tan"gram\, n. [Cf. Trangram.]
A Chinese toy made by cutting a square of thin wood, or other
suitable material, into seven pieces, as shown in the cut,
these pieces being capable of combination in various ways, so
as to form a great number of different figures. It is now
often used in primary schools as a means of instruction.
[1913 Webster]
WordNet (r) 3.0 (2006):
tangram
n 1: a Chinese puzzle consisting of a square divided into seven
pieces that must be arranged to match particular designs