hardening;  vulcanization;  hardening (of attitude, stance, etc.);  stiffening;  upturn (in the market);  firming up
 hard-liners;  diehards;  (young) man with traditionally masculine interests;  tough boy;  hard news;  reporter who covers political and economic affairs
 bone;  firm;  uncompromising
 stiffening;  rigidity;  rigor;  stiffness;  ossification;  petrification
 firm;  strong;  unbending;  unyielding;  uncompromising;  stubborn
 hard ball;  regulation ball
 cemented carbide;  superhard;  ultrahard
 hardness and softness;  hard line and moderate line
 crude;  immature;  unpolished
 hard (esp. of hardball, tennis, etc.)
 train ticket printed on thick paper
 high-contrast (photography);  hard tone;  bullish (market);  firm
 sclerophyll forest;  sclerophyllous forest;  hardwood forest