From Longman Dictionary of Contemporary Englishlook somebody up and downlook somebody up and downLOOK ATto look at someone carefully from their head to their feet, as if you are forming an opinion about them → look
Examples from the Corpus
look somebody up and down• "Don't be silly - you don't need to lose weight, " he said, looking her up and down.• Ron Barton looked her up and down.• She looked him up and down.• The hotel manager slowly looked the old man up and down and then asked him to leave.• The guy looked him up and down and then something clicked.• She stood there, looking Sherman up and down, as if she were angry.• Raul looked him up and down, eyes opened wide with derision.• Every day after the first two weeks I would look anxiously up and down the road, hoping to see their car.• The eaters were lo-cals; they looked us up and down when we went in. 