pop festival

Unknown in 1960 but 10 years later had exploded before declining after 1975.
http://books.google.com/ngrams/graph?content=pop+festival&year_start=1960&year_end=2008&corpus=15&smoothing=2&share=

chicken tikka masala

Sometimes claimed as a British "national dish" it was little mentioned before
1985. More at http://en.wikipedia.org/wiki/Chicken_tikka_masala
http://books.google.com/ngrams/graph?content=chicken+tikka+masala&year_start=1970&year_end=2008&corpus=15&smoothing=2&share=

latchkey kid

A latchkey kid or latchkey child is a child who returns from school to an empty
home because his or her parent or parents are away at work, or a child who is
often left at home with little or no parental supervision.

It's said to have been coined in 1944 but took some decades to catch on.

See more at http://en.wikipedia.org/wiki/Latchkey_kid
http://books.google.com/ngrams/graph?content=latchkey+kid&year_start=1900&year_end=2008&corpus=15&smoothing=2&share=

motorist

http://books.google.com/ngrams/graph?content=motorist&year_start=1900&year_end=2008&corpus=15&smoothing=0&share=

filling station

A place to buy petrol for your car. Initially marks the rise of mass-ownership of
cars but perhaps then becomes so commonplace that it's less often written
about
http://books.google.com/ngrams/graph?content=filling+station&year_start=1900&year_end=2008&corpus=15&smoothing=0&share=

garden centre

A place to buy plants amongst other things
http://books.google.com/ngrams/graph?content=garden+centre&year_start=1950&year_end=2008&corpus=15&smoothing=0&share=

geek,nerd

The words "geek" and "nerd" seem to have grown from around 1980
http://books.google.com/ngrams/graph?content=geek%2Cnerd&year_start=1950&year_end=2008&corpus=15&smoothing=0&share=