Denshi Jisho — Online Japanese dictionary

伸びる のびる 1: to stretch; to extend; to lengthen; to spread;
2: to make progress; to grow (beard, body height);
3: to grow stale (soba);
4: to be straightened; to be flattened; to be smoothed;
5: to be exhausted
Common word, Ichidan verb, Intransitive verb 

You can also

Look up kanji details for 伸びる.

Try a Yahoo Jisho search for 伸びる .
Try a Goo Jisho search for 伸びる .
Try a Google search for 伸びる .