1) a person far below the range of
normal height. Being extremely short but otherwise in proper proportion is not a medical diagnosis; the term "midget" is not a medical
one. However, the broader term "short stature" (<5th percentile or under about
5'5" for men/5' for women) is used, but like "midget" is not a medical diagnosis unless it is due to hormonal problems.
2) (slang) a man 5'5" or shorter.
This is what I think the height categories are (men):
5'
1" or under Midget
5'2"-5'3" Very
Short
5'4"-5'5"
Short
5'6"-5'7" On the short side
5'8"-5'9" Not that tall
5'10"-5'11" On the tall side
6'-6'2" Tall
6'3"-6'4" Very Tall
6'5"+ Giant