misled: Once, I thought this was the past tense of misle. Not all dictionaries have that.
thereat: I saw this in a form lease for an apartment. It said, approximately, that it would violate the lease to loiter in the front courtyard or to play “thereat”, which I guessed was pronounced /THII-ree-at/. The lease didn't mention any other game, so singling out “thereat” in a lease meant it must have been extremely dangerous. I wondered what kind of game was so threatening that it required a stand-alone mention in the lease, or even that it's still a game. I couldn't remember having played a game that. I don't recall how long it took me to recognize this one.