Shakespeare's sonnet 18 use of "Dimm'd" and "Untrimm'd"

The sentences are:

"...
Sometime too hot the eye of heaven shines,
And often is his gold complexion dimm'd;
And every fair from fair sometime declines,
By chance or nature's changing course untrimm'd;
... "

It depends on what school of grammar you follow.
Traditional grammar would call them past participles, postmodifier of the preceding noun.
Modern grammar theory would call them verbs. But they are not finite verbs.

dimmed - diminished, faded, (like when a cloud occludes the sun)
untrimmed - uninhibited

They are past participles used adjectivally or to form the passive voice (depending on interpretation).

AlpheccaStarsuntrimmed - uninhibited

I think this interpretation is debatable. According to various sources, "untrimmed" is thought to refer either to loss of decoration or (metaphorically) to the sails of a ship not being properly adjusted. Anyway, the way I read it, "untrimmed" has to refer to something that diminishes "fairness".

By chance or nature's changing course untrimm'd;

Either by sheer chance, or by the natural, uninhibited course of nature (nature left to find it's natural way)

AlpheccaStarsBy chance or nature's changing course untrimm'd;Either by sheer chance, or by the natural, uninhibited course of nature (nature left to find it's natural way)

I guess this is one interpretation. I tend to think that "untrimmed" modifies "fair", not "nature's course". But I see there is no real agreement about this amongst commentators.

At first, I thought "untrimmed" meant something like "uninhibited" (as suggested by AlpheccaStars), so I assumed it modified "nature's course"; but given that one of the definitions of "untrim" is "to deprive of elegance or adornment, to strip of trimmings", the two lines may in fact refer to so

ozzourtiAt first, I thought "untrimmed" meant something like "uninhibited" (as suggested by AlpheccaStars),

I was thinking of the phrase "to trim one's sails" which is one method of steering or controlling the course of a sailboat. And all ships in Shakespeare's day were either rowed or wind-powered. The powerful Spanish Armada had been defeated by the Englis

Yes, I'm more or less familiar with the concept of sail trimming. I also wonder if "untrim" with the meaning I suggested in my previous post was reasonably popular back in Shakespeare's day.

ozzourtiI also wonder if "untrim" with the meaning I suggested in my previous post was reasonably popular back in Shakespeare's day.

Shakespeare was extremely creative in his use of language. A meaning did not have to be popular for him to use a word, and it is claimed that he invented a lot of the English lexicon!