As people made sense of its multiple meanings ...
Lookups spiked on December 30, 2010.
Although the New Year's sense of resolution is well known ("a promise to yourself that you'll make a serious effort to do something"), people were probably looking it up to explore the word's different meanings.
After all, a resolution can also be the act of finding an answer to something, the sharpness of a television image, or the change of notes in a chord that releases musical tension.
So how did a single word come to mean such different things?
The answer lies in resolution's Latin root, which meant "the separation of something into smaller or simpler parts."
The "New Year's resolution" sense evolved because breaking into smaller parts is a way to understand a complicated problem - and a way to come up with a clear answer. That answer can be a firm decision or promise - a resolution.