Brit–covenant. Brit Ahuvim is the term Rachel Adler coined to refer to her “Lover’s Covenant.”
B’deiavad–after the fact, ie too late to have fixed the thing when it should have been fixed.
Chuppah–the wedding canopy under which bride and groom stand when they get hitched
d’Oraita–Torah law, which has a very seriously binding status
d’Rabbanan–Rabbinic law, which generally has the same weight as Torah law, but tends to involve more leniencies in doubtful (safek) cases
Get–Jewish writ of divorce. Only the man can give a get to a woman, so if she wants to get divorced and he doesn’t (or he’s being vindictive, or many other sorts of things), he can refuse to give her one and she’s basically stuck married to him, and doesn’t always have a lot of recourse. Many folks today are trying to figure out how to have a kosher wedding that doesn’t put the woman at risk of being stuck someday without a get.
Kesef–money, often these days a ring or other valuable metal thing
Kiddushin–aka erusin, aka betrothal, aka the first part of the wedding ceremony. For more info, go here.
l’hatchila–at the outset
Maneh–a form of ancient money. See peruta
Minhag–custom, non-halakhic tradition that sometimes develops, over time, the weight of halakha
Neder, Nedarim–vow, vows.
Niddah–the state in which a woman is when she has her period, and for a bit after, during which she does not have sex with her partner. More information here.
Nisouin–the 7 brachot/blessings, aka the second part of the wedding ceremony
Peruta–an ancient value, akin to a dollar or a shekel or yen now. I don’t remember offhand how much it’s worth these days.
Safek–doubtful, ie it’s not clear if the status of a thing is X or not
Vedai–certain, ie the thing definitely has the status of X