UNDERSIZE Meaning of UNDERSIZE in English un ‧ der ‧ sized /ˌʌndəˈsaɪzd◂ $ -ər-/ BrE AmE ( also un‧der‧size /-ˈsaɪz◂/) adjective too small Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012