I am sure we have discussed before how many words change their meaning with time. I have called them Aladdin words to signify the Genie's 'your wish is my command' to hint at popular usage.
I recently came accross the earlier uses of silly.
From c 1550 to c 1675 silly was very extensively used in senses 1-3, and in a number of examples it is difficult to decide which shade of meaning was intended by the writer.(OED)
1. Deserving of pity, compassion, or sympathy
Helpless, defenceless; esp of sheep and animals
 2. Weak, feeble, frail; insignificant, trifling.
 3. Unlearned, unsophisticated, simple, rustic, ignorant, humble, simple, rustic.
By the 16th c. the current meaning of foolishness becomes apparent.
1588 SHAKES. Loves labours lost. III. i. 77 By vertue thou inforcest laughter, thy sillie thought, my spleene.
1721 WODROW Hist. Suff. Ch. Scotl. (1722) II. 318 He did not recover the Exercise of his Reason fully, but was silly, and next to an Idiot.

In the 20th c the predicative use — to drink yourself silly, or to play silly buggers— emerges implying foolish to an excessive degree.
An interesting transmogrification. What next?

Nice is a very similar word that has changed its meaning over the centuries, almost in the opposite direction to silly.

From The Online Etymology Dictionary:

quote:

c.1290, "foolish, stupid, senseless," from O.Fr. nice "silly, foolish," from L. nescius "ignorant," lit. "not-knowing," from ne- "not" ... + stem of scire "to know." "The sense development has been extraordinary, even for an adj." [Weekley] -- from "timid" (pre-1300); to "fussy, fastidious" (c.1380); to "dainty, delicate" (c.1405); to "precise, careful" (1500s, preserved in such terms as a nice distinction and nice and early); to "agreeable, delightful" (1769); to "kind, thoughtful" (1830). In 16c.-17c. it is often difficult to determine exactly what is meant when a writer uses this word. By 1926, it was pronounced "too great a favorite with the ladies, who have charmed out of it all its individuality and converted it into a mere diffuser of vague and mild agreeableness." [Fowler]

I remember my English teacher agreed with Fowler; if anyone used nice in work handed in to him it was sure to set him off on a rant about what a lily-livered, namby-pamby sort of word it was.

We have discussed this before (link).

[QUOTE]Originally posted by zmježd:
We have discussed this before [quote]

Yes, quite right. I started by saying: I am sure we have discussed before how many words change their meaning with time. I had hoped it might open a discussion of other examples of semantic drift.

I had hoped it might open a discussion of other examples of semantic drift.

Sorry, I was in a hurry. Both arnie and I pointed out the other standard example which is nice. I think it would be difficult to choose a common word in any language, study its history and usage, and not find some degree of semantic shift. Some other examples that we have discussed are: gay, drive, decimate, infer, and imply. Many of these words evoke strong emtions in people who feel that semantic drift is a bad thing because it leads to a degradation of the language and a breakdown in communication. Others note that mmost words in a language have more than one meaning. In fact, words with a single meaning oftentimes are rare or specialist words. Something I've pondered is how a single word is the most ambiguous thing. Words need to be placed into groups syntactically for them to have more precise meanings through context. If I say dog, you cannot be sure if it's some kind of canine, a verb, or a slur, but when I begin to put that word in context my intended meaning becomes clearer: "I went to the dog races yesterday." I am, no doubt, pointing out the obvious, but it seems to me that many forget this fundamental property of words: they are rarely used in isolation from other words. So, when a coworker bemoans to me the fact that decimate doesn't mean 'to reduce a military group by one-tenth (for disciplinary reasons)' any more but has come to mean 'to destroy (something)', I have to wonder if an example of its Latin meaning is extant in English literature aside from translating Caesar or some other Roman historian. Besides these imafmous words, there is a whole host of others that pass by without comment. Some of my favorites are mole and file. The latter particularly, because unlike the former, it is a single word whose meanings have spanned quite a history.

garble originally meant "sift, take the pick of", apparently from Latin crībum "sieve". Now it means "mix up or distort to such an extent as to make misleading or incomprehensible".