Tom is less athletic than Tim.的同义句Tom is _____ _____ ____ _____ Tim.

less...than...
=not as/so...as...“不如，少……”形容词比较级用法“不及……如……”

Tom is less athletic than Tim.
=Tom is not as/so athletic as Tim.

less...than...=not as/so...as...表示“不如，少……”

套用这个格式，答案就是not as/so athletic as

not as/so athletic as