Single-word request for words that do not mean quite the same thing as before

I'm looking for a word that describes words that do not mean the same thing as before, for example, due to over usage.

For example, the word glitch.

a sudden, usually temporary malfunction or fault of equipment.

'Somebody help Tom, he's glitching out.'

In this case, the word 'glitch' usually refers to the malfunction of machineries, but has been used in the context of humans. It still does embodies part of its meaning in this case, but definitely not the 'equipment' part.

So, I'm wondering is there a word used to describe this behaviour of usage of the words.

Solution 1:

If a compound word will do, we may suggest some because no single word is readily available at hand even in the hand of great etymologists. Wikipedia suggests

SEMANTIC SHIFT

SEMANTIC PROGRESSION

SEMANTIC DRIFT

SEMANTIC CHANGE to which we like to add
one more, SEMENTIC FLUXES.

WORDS change because they are constantly used and, in course of such usage, some become blunt, some sharper,some widen while some become narrow, some are lost in the maze of similarities/associations where as some others take refuse in contrasts.

Figure of Speech plays a major role in this change, though certainly not all.

Strange are the ways of such changes. Otherwise, 'NICE' once meaning foolish, now, means agreeable and SILLY originally meaning 'happy' now comes to mean foolish.

One more point. Use of the term "original" in respect of a word is relative. This is termed as "etymological Fallacy". In our quest for word-meaning there must be a point in known history beyond which it is shrouded in mystery, so to say, this-far-no-further point. Who knows the 'Word' may have yet another totally different meaning earlier!