Are there any pairs of English words that are cognate to each other yet have opposite meanings?

Question

Alright, here's the best way I can explain this: if, hypothetically, the word pairs (love, loathe) and (friend, fiend) were cognates (i.e. they shared an etymological ancestor), they would be precisely what I'm looking for. These pairs aren't cognates, of course, but what I'm trying to get at is that if they were, they'd fit my criteria: antonyms that are also cognate to one another.

So, now that that's explained, I have to ask: does anyone know of a real, non-hypothetical duo of words of the type I'm describing? Also, I realize this is the English language board, but if for some reason anyone happens to know of an example of this from a language besides English, please do consider chiming in anyways. Failing that, really any other relevant info or insight would also be a huge help, as I'm pretty much at a loss for leads on this one.

Thanks in advance~

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NOTE: as far as this specific request is concerned, I'm not interested in either:

• contranyms/auto-antonyms (e.g. fast can mean both "quick" and "unmoving")
• antonyms that only differ in their affix (e.g. attach, detach; careful, careless; etc.)

Those two things aside, however, I'm really just looking for any two cognates with contrasting meanings. Whether they're direct, binary opposites (e.g. true, false) or a more subjective sort of opposites (e.g. float, sink), I'm all ears. I'd even say feel free even to compare words across different parts of speech (e.g. alive, death) – just so long as they're English cognates whose definitions clash with each other, that's what I want to find at least one veritable example of, if only to say that I can.

***Update! Here's what I have so far:
black and blank from PIE *bhel- (h/t John Lawler)
shirt and skirt from PIE *sker- (h/t Xanne)
potion and poison from PIE *peh- / *po(i)- (h/t Matthew Roberts)
guest and host from PIE *gʰóstis / *ghos-ti- (my own discovery)

Answer 1

Just thought of another possible example: ward and guard. There are quite a few w- words in English that have a French gu- doublet: warranty and guarantee, warden and guardian, William and Guillaume, war and guerre. From what I can gather, the Germanic w- is the older sound, the gu- variations developing later in France, and introduced into English with the Norman invasion.

But for our purpose: guard means to defend, whereas a ward is someone who is being defended (as in a “ward of court”). Like my previous suggestions, these words aren’t quite antonyms, but they do have opposing meanings. Sort of.

Answer 2

I love this kind of thing. I came across cognates and doublets when studying linguistics at university. I like Phil Sweet’s suggestion of fox and vixen. I can only think of a couple of suggestions, and I’m not entirely sure they will meet your criteria, Kyle O’Brien, but I’ll post them for what they’re worth (if anyone is still following this thread).

• potion / poison—my (admittedly rather thin) argument being that poison is always something harmful, lethal, whereas potions are, or rather were, usually curatives, concocted back in the day by the local white witch of the village to treat some ailment or other;

• cannabis / hemp / canvas—cannabis is the plant cultivated for its medicinal and recreational properties; hemp is the material made from the plant, which contains no cannabinoids; and canvas, a more general term for cloth or fabric, also happens to derive from the same root (Greek: kannabis) so I thought I would add it as well.