It compared the "what is" queries from this year with 2011 and found that "what is love?" had the most amount of traffic over a sustained period in 2012 compared with last year.
Love was followed in the "what is" category by iCloud, 3G and Scientology.
Google, which has faced public anger alongside other multinational companies Starbucks and Amazon about dodges used to reduce corporation tax liabilities, also revealed the top-trending people of 2012.
Singer Whitney Houston, who died in February, topped the list, followed by the Duchess of Cambridge and Take That star Gary Barlow.
Euro 2012 was the top-trending search of 2012, followed by Olympic tickets.
Andy Murray was the most searched for British Olympian, and Usain Bolt topped the global Olympian category.
Children's series Mike The Knight was the top-trending TV show, followed by thriller Homeland and Towie.
Gangnam Style, by South Korean singer PSY, was the top-trending song.
X Factor star Lucy Spraggan, who had to pull out of the show because of ill health, was the top-trending music artist, and Jeremy Hunt topped the politicians list, followed by London Mayor Boris Johnson.
Google defines trending searches as queries that have had the highest amount of traffic over a sustained period in 2012 compared with 2011.