Lawntennis is likely misspelled.
Lawntennis has no English definition.
As a noun badminton is
a racquet sport played indoors on a court by two opposing players (singles) or two opposing pairs of players (doubles), in which a shuttlecock is volleyed over a net and the competitions are presided by an umpire in British English and a referee in American English.
As a proper noun Badminton is
a village in Gloucestershire, England.