Denshi Jisho — Online Japanese dictionary

主体 しゅたい 1: main constituent; core; nucleus;
2: subject (philosophical); protagonist
Common word, Noun 
主体 しゅたいてき independent; responsible; active; proactive
Common word, Na-adjective 
主体 しゅたいせい independence; individuality
Noun 

You can also

Look up kanji details for 主体.

Try a Yahoo Jisho search for 主体 .
Try a Goo Jisho search for 主体 .
Try a Google search for 主体 .