un ‧ der ‧ de ‧ vel ‧ oped /ˌʌndədɪˈveləpt◂ $ -dər-/ BrE AmE adjective
1 . underdeveloped country/region etc a country, area etc that is poor and where there is not much modern industry ⇨ developing country
2 . not having grown or developed as much as is usual or necessary:
a baby born with underdeveloped kidneys
—underdevelopment noun [uncountable]