Good fortune, and harmony. It predates the symbol you're probably thinking of :D
卍 (left-facing, counter-clockwise) → Common in East Asia, especially Japan and China, for Buddhist temples and meanings like good fortune, balance, and eternity.
卐 (right-facing, clockwise) → Found in India and other places, also positive originally, but this is the one Nazi Germany adopted in the 20th century, twisting its meaning in the West.
卍 is used to represent a temple on maps in Japan. I think they had a plan to replace it at one point, but I'm not up to date on how that went.
卍 was adopted by China and then exported to Japan, so it's the only one of the two that has a Japanese reading. 卐 is not kanji (AFAIK). I looked it up and @Anonymous123 is correct.
I will, however, say that the validity of the sources is questionable. Dictionaries and databases often make mistakes and fold things together erroneously.
Where did you see it? Was it on a map, a building (temple), some sort of slang, a name?
Was it Tokyo Revengers?
Edit: I couldn't really figure out whether or not 卐 (what Japanese people usually refer to as 右卍) was/is used in Japan. It's clearly stated to be an alternate variant of 卍 (異体字), but it's not clear to me if that makes it a "kanji" or simply states that it's a "foreign" version of 卍, that's not in use. Anyway, I guess it's technically a kanji and I should stop thinking about it.
The panel with the text reads as "四宮先輩, まじ卍っす…" = "Shinomiya-senpai… that's seriously epic/crazy/intense…" (at least that's what I think it says)
That's from Kaguya-sama right? Yeah, it's probably "Shinomiya-senpai…really?!" in the "are you serious?!" sense.
Edit: Found it:
The other two are... questionable (without context) XD
The guy with the armband is Schrödinger from Hellsing (set during WW2, so the meaning is what you'd expect).
The last one (the girl) is Excel from Excel Saga. Not sure if that's official or just making fun of the scene where she does that weird "Hail Ilpalazzo" thing. I think it's supposed to be satire, but I haven't watched the show.
Edit: Found the clip, it's official. Pretty funny at that :D
..I saw it on like some manga what would It mean there? 
