undeveloped

• undevelopt (obsolete)

From un- + developed.

undeveloped (not comparable)

1. Not developed or used.

   Synonyms: primitive, rudimentary, unrefined; see also Thesaurus:crude

   Antonyms: developed, refined, sophisticated

   • 1952 January, “Electrification Progress in Norway”, in Railway Magazine, page 54:

     These developments, most of which have taken place during the past 30 years, are remarkable in view of the low traffic density, except in the neighbourhood of Oslo, and the very extensive undeveloped areas of mountain and virgin forest.

   • 2025 February 6, Josh Robbins, David Aldridge, Zach Powell, “Kings to acquire Jonas Valančiūnas from Wizards for 2028, 2029 draft picks”, in New York Times‎^[1]:

     We now also know adding Valančiūnas also yielded a pair of future second-round picks and another young wing (Cissoko) with positional size (and an undeveloped skill set).

2. not built on, unbuilt; not ready for building on

   Antonyms: built-up, developed

   Near-synonyms: empty, vacant

   • 2025 December 26, “Saudi Arabia introduces new White Land Rules, imposes fines up to 100% on undeveloped plots”, in Times of India‎^[2]:

     The message from the authorities is straightforward: undeveloped land within city boundaries should no longer be treated as a passive investment, it must be used productively.

3. lagging behind others, especially in economic or social matters

   Synonym: developing

   Antonyms: advanced, developed

   Near-synonym: third-world

   • 1958 May, Stevan Dedijer, “The Birth and Death of a Myth”, in Bulletin of the Atomic Scientists, volume 14, number 5, page 164:

     Running as full of enthusiasm as they can, some undeveloped countries are falling farther behind—their needs are growing faster than their achievements.