Webster's 10th Collegiate is as ambiguous as it gets:

1 a : to examine or consider with attention and in detail : STUDY

b : to look over or through in a casual or cursory manner

2 : READ; especially : to read over in an attentive or leisurely manner

I think M-W is ahead of the curve on this; let's see what our old friend Michael Quinion has to say about it:

http://www.quinion.com/words/qa/qa-per1.htm