To procrastinate in a semi-productive way
I erruviated so much yesterday: instead of doing my essay, I organised all my DVDs alphabetically.
To procrastinate (often from study or homework) in a productive manner (e.g. to learn something which is unrelated to what you should be learning)
Amy should have been writing an essay, but she erruviated for an hour to learn some new Italian words.
by doing activities that are useful, but not getting round to the task in hand, eg. cleaning your room to avoid writing an essay.
Last night I erruviated for hours and ended up learning some Italian.