1. to be missing London while one is away2. sypmtoms often associated with those of homesickness- but does not require one to have permanently resided in London3. sometimes, but not always, a result of wanderlust4. an incesant, inexplicable need to return to the the city on the Thames5. pure. simple. sanity.
She sat alone, sipping her tea, feeling so Londonsick it was almost unbearable.