The meaning of words often evolves and changes over time, which poses an issue for us. Those who have the most control over language and other elements of culture in a capitalist society are, of course, the capitalists, and they know how to weaponize it
There's a number of ways that language is weaponized, but a common one is rendering revolutionary language devoid of meaning by using it in unrevolutionary and even counterrevolutionary ways
'Socialism' is an obvious example of this. They are currently trying to neuter the term, making it equivalent with anything state-funded in capitalist countries, even calling the police and military of an imperialist state 'socialist'!
This poses a multitude of problems for us, as it interferes in clear communication in the topic and makes it easier for forces of reaction to mislead those who aren't already well-versed in socialism
While of course not all changes are due to intentional work to change the meaning of words, there is no doubt that the capitalists have realized the power in language
I think you have some comrades who ignore the very real issue of conscious conspiracies by capitalists. Even without those conspiracies the entire culture of capitalism can be damaging, and often it's a mixture of both, but that's a thread for another day
Ironically this is a perfect demonstration of capitalist control of language- who funds polysci departments, controls colleges? Of course they teaches that socialism has nothing to do with Marx, college is an indoctrination tool of the capitalist class.
As Marx says "the class which has the means of material production at its disposal, has control at the same time over the means of mental production, so that thereby, generally speaking, the ideas of those who lack the means of mental production are subject to it."
Now of course the most important part of analyzing this attack is how do we confront it. Inventing tons of new words is hardly a viable or long-term solution, so losing the meaning of socialism, of decolonization, of imperialism, etc, is very damaging.
Those words allow us to convey complex concepts in one word, to have simple slogans we can shout and put on signs, and a language that allows us to communicate with those who have learned it.
I think 'those who have learned it' gives us the clue of how to fight- by clearly defining those terms whenever we can. In conversation, in pamphlets, etc.. Whenever people seem unsure make sure to clearly define your language.
Moroccan revolutionary Ben Barka (I'm almost done scanning this, the pdf will be up soon) speaks about this difficulty in the anti-imperialist movements of Africa. He notes that changing situations can likewise impact language. 
Using the example of 'unity'- a revolutionary word against empire- he explains how the imperialists are working to coopt it- a unified Africa under imperialist rule. He concludes that we must clearly define what these terms and slogans mean materially
We need to have clear definitions, I think decolonization is one that's come up a lot recently- what does that materially look like? Without that it's just a way to sound 'woke'. With a clear plan of what decolonization and socialism look like, they're powerful words.
It is of course semantics to defend revolutionary language, but it's necessary semantics. Nothing is more important to socialist movements than communicating ideas, we must fight the capitalists' attack on our communication
