Misses US Army man Stevenson (5)
I believe the answer is:
girls
'misses' is the definition.
('girl' can be a synonym of 'miss')
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for girls that I've seen before include "Young ladies" , "Members of brownies or guides - one of the 14 films" , "Youthful females" , "Female children" , "Young females" .)