Ranked by relevance and common usage.
Keep "unpenetrated" when the sentence already sounds natural, when a synonym would add unintended emphasis, or when readers need the most familiar wording. A synonym should clarify or sharpen the message, not simply make the sentence look more varied.
If two options seem close, choose the one that best matches the audience and purpose of the sentence.
Choose a synonym only if it keeps the core idea of "unpenetrated" intact in the sentence you are editing.
Check whether the replacement sounds more formal, casual, emotional, technical, or forceful than the original word.
Read the full sentence after the swap. Keep the synonym only when the sentence becomes clearer or more precise.
Review note: Synonym lists are ranked with lexical data and reviewed for practical writing value. Use the comparison notes, sentence evidence, and source labels together; a high-ranking synonym can still be wrong when the audience, register, or grammar changes.
After choosing a replacement for "unpenetrated", read the sentence once for meaning and once for rhythm. The best synonym should feel natural in the full sentence, not only accurate in a word list.
If the synonym makes the sentence slower, vaguer, or more dramatic than intended, keep "unpenetrated" or choose a simpler alternative from the closest-match group.
3 total sentences available.
Or call him, if you will, an American Backwoodsman, who had to fell unpenetrated forests, and battle with innumerable wolves, and did not entirely forbear strong liquor, rioting, and even theft; whom, notwithstanding, the peaceful Sower will follow, and, as he cuts the boundless harvest, bless."
Source: wiktionary
Both in Central America and in Orinoco there yet are many unpenetrated forests which are almost entirely composed of wild cacao-trees.
Source: wiktionary
"We asked him to explain more precisely the situation of this fountain, and he said: 'You are doubtless aware that perpetual darkness surrounds the pole unpenetrated by any ray of light till God permits.
Source: wiktionary
Closest matches include unpierced.
Compare the replacement against real sentence context. This entry includes sample sentences so you can check tone, grammar, and meaning before swapping words.