Wordnet 3.0
NOUN (2)
1.
any game designed to exercise the intellect;
2.
deliberate actions of calculated psychological manipulation intended to intimidate or confuse (usually for competitive advantage);
- Example: "football players try to play mind games with the opposition"- Example: "the jeweler's mind game is to convince lovers that the size of a gemstone reflects the depth of their feelings"
WordNet (r) 3.0 (2006):
mind game
n 1: any game designed to exercise the intellect
2: deliberate actions of calculated psychological manipulation
intended to intimidate or confuse (usually for competitive
advantage); "football players try to play mind games with the
opposition"; "the jeweler's mind game is to convince lovers
that the size of a gemstone reflects the depth of their
feelings"