underweight
US /ˌʌn.dɚˈweɪt/
UK /ˌʌn.dɚˈweɪt/

1.
niedowaga, zbyt lekki
below a weight considered normal or healthy
:
•
The doctor said the baby was slightly underweight.
Lekarz powiedział, że dziecko jest lekko niedowaga.
•
She was concerned about her dog being underweight.
Martwiła się, że jej pies ma niedowagę.