iron (Fe);  strong and hard (as iron);  railway;  railway enthusiast
 hot (thing);  passionate (feelings, etc.);  ardent;  hot (e.g. temper);  zealous;  enthusiastic;  intense
 inside;  within;  while (e.g. one is young);  during;  among;  amongst;  in (secret, chaos, poverty, etc.)
 forging;  tempering;  drilling;  training;  disciplining