Denshi Jisho — Online Japanese dictionary

理系 りけい science
Common word, Noun, No-adjective 
理系離れ りけいばなれ flight from science
Noun 
理系ばなれ りけいばなれ flight from science
Noun 

You can also

Try a Yahoo Jisho search for りけい .
Try a Goo Jisho search for りけい .
Try a Google search for りけい .