Some words are both nouns and verbs (or rather, there are words with like etymology and spelling but one is a noun and the other a verb) but in at least some standard dialects are pronounced differently to one another.
An example is 'estimate': as a noun it rhymes with 'foot'^; as a verb with 'fate'.
Is there a name for this in linguistics?
(^in dialects without a long 'oo' anyway!)
In English, stress has a grammatical function: it can be used to differentiate between nouns and verbs in words with like etymology and spelling, as you observed. In your example, 'estimate' as a noun has an unstressed final syllable: /ˈɛs.tɪ.mət/. As a verb, it has secondary stress on the final syllable: /ˈɛs.tɪ.ˌmeɪt/.
The most commonly cited example of this phenomenon is the noun 'insult' with primary stress on the first syllable /ˈɪn.sʌlt/ vs. the verb, which has primary stress on the final syllable /ɪn.ˈsʌlt/.
You'll notice that the stress differences between noun and verb are not always identical, but the key is that the word-level stress pattern changes between noun and verb.
We can refer to this phenomenon as stress differentiation of part of speech in English (or simply 'using stress to differentiate part of speech'). In cases where the verb existed before the noun, we sometimes refer to the process of deriving the noun as initial-stress derivation.
The short answer is heteronym: a pair of words with the same spelling, different pronunciations, and different meanings (even if the words and meanings are closely and etymologically related).
The longer answer is "it's complicated." Consider the chart under "Related terms" in the Wikipedia entry for "homonym". For one thing, the requirement that homonyms have the same pronunciation is treated fairly flexibly, and the term is sometimes extended as an umbrella, and the requirements of the "related terms" are not rigidly enforced.
