What does one call a similar inflections of a root with different morphological classes as?

Question

In a morphologically rich language, it is quite common that a root might have multiple inflections, each representing a different morphological class.

Here multiple inflected word forms of a root might look the same as well. What do you call such words which have the exact spellings but differ in their morphological classes?

For example the first, second and third person past tense of arrive is arrived. Here all the three have different grammatical categories as person is differemt, but they still have the same inflected word form. HEre, we have same word form with the same meaning, but its grammatical functionality in each is different making them inflectionally different.

Can they be called as homonyms? If it is word level homonym isn't it necessary that the meaning is different If it is affix-level homonymy, isn't it applicable only to derivational affixes?

But the fist person and third person present tense of arrive are different (arrive and arrives).

Any help would be appreciated.

Answer 1

The usual term for this is "syncretism".

My understanding is that there is a fair amount of debate about the best way to analyze cases like these, although I don't know how much of this is about splitting hairs. For example, I recently ran across the following abstract (unfortunately, I haven't gotten to read the paper yet):

The paper rejects the standard view according to which every tensed verb in English agrees with its subject in person and number. It argues that person is irrelevant to all verbs except BE, and that past-tense verbs and modals (other than BE) have no number agreement features.

"Subject–verb agreement in English", by Richard Hudson, English Language & Linguistics Volume 3, Issue 2 November 1999 , pp. 173-207

There is a WALS chapter "Syncretism in Verbal Person/Number Marking" (by Matthew Baerman and Dunstan Brown) that has a brief discussion of English in the "Theoretical implications" section.

Answer 2

What do you call such words which have the exact spellings but differ in their morphological classes?

identical surface forms

You can also specify if they are morphological variants of the same lemma, as opposed to forms of distinct lemmata or distinct roots.

Can they be called as homonyms?

Yes, they are technically also homonyms, but it is not very specific.