isthmoid

/ˈɪsmɔɪd/
adjective
  1. Shaped like or resembling an isthmus; narrow and connecting two larger parts.
    • Geologists described the land bridge as isthmoid in form.
    • The isthmoid passage between the two valleys was barely wide enough for a single car.
    • The isthmoid shape of the sandbar connected the island to the mainland at low tide.
Synonyms
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