Google Search now shows word popularity chart along with its definition
I was amused to expand the panel for a word meaning provided by Google's define feature ... and was impressed with the graph showing the popularity/usage of the word over the last 200 years sourced through Google's Ngram Viewer Funny things happen though when information is mashed-up from separate sources. For the word "nerd", there is a note that the word originated in the 1950s (originally US) but the chart shows it has been around since the 1800s. It probably meant something else earlier. Also see: Track & learn about Aphonetic Words