Many dictionaries have a separate entry for
enamo(u)red, identified as an adjective. The OED is one dictionary that does this but, for some reason, the online Oxford has only an entry for
enamor (or
enamour in the UK English dictionary). Even so, the online Oxford provides a definition only for
be enamo(u)red of/with/by: "Be filled with a feeling of love for", or "Have a liking or admiration for".
The dictionaries that have entries for both
enamo(u)red, as an adjective, and
enamo(u)r, as a verb, will note that the verb is usually used in the passive. Perhaps the reason it's so hard to come up with a sensible sounding sentence that uses
enamo(u)r is the problem of identifying the subject of such a sentence. For example, if I am enamoured of roast vegetables, who or what is doing the enamouring?
An example using
enamor that seems to work appeared in a November 2020 article "The Most Influential Style Icons In Music History" on the UPROXX website:
The underground popularity of N.W.A. helped enamor a certain kind of teenager with the look of California street gangs...
Here we have three entities interacting: the popularity of hip hop group N.W.A., a certain kind of teenager, and the look of California street gangs. The first enamors the second with the third.
Even if no dictionaries listed
enamo(u)red as an adjective, and it was deemed only to exist as the past participle of
enamo(u)r, I would still feel it was justified to reserve common status for
enamo(u)red and class other forms of the verb as rare. We don't always class every inflection of a verb in the same way. Back in November
I changed mooting to rare, while leaving
moot and
mooted as common. But in this case there's authority for treating
enamo(u)red as a word in its own right, so I have even less hesitation in leaving
enamo(u)r as a rare word (and
enamo(u)ring also).