Geek:
A geek is someone who is unusually enthusiastic about a specific topic, sometimes an unusual topic, such as computing, science, maths or painting tiny models from Lord of the Rings.
Boffin:
A term used almost exclusively in the UK to affectionately refer to an expert or egghead. This term originated from the 'back room boys' in the second world war who were, amongst other things, operating radar and trying to break the german enigma code.
Nerd:
Someone who has difficulty negotiating social situations. The term has strong negative connotations and is mostly used as an insult. Nerd is often used interchangably with geek and it is true that many people are both but they mean different things.
Geek/Nerd/Boffin
Geek:
"OMG OMG IT'S A TINY PAINTED IAN MCKELLEN!"
Boffin:
Spitfire pilot 1-"Biggles have you heard the news?"
Spitfire pilot 2-"No, what is it jeffrey?"
Spitfire pilot 1-"The boffins have cracked the enigma code!"
Spitfire pilot 2-"Excellent; lets get up there and give those germans a taste of our good old British spunk, bristol fashon, six of the best trousers down!"
Nerd:
Normal person-"Well this is a fine state of affairs!"
Nerd-"Is it... I though it was a disaster?"
Normal person-"OMG I was being sarcastic. You are such a nerd!"
Precedes or follows either a gratuitously disrespectful or honest remark, originated in New York City. Used in similar fashion to "no offense" or "to be honest," interchangeably.
Ya mans is wild buns, respectfully. Respectfully he's washed.
After school, The Modells on Jamaica Ave was active. Respectfully.
Adjective. Used to describe persons who have adjusted or altered their lifestyle for environmental reasons. Crunchy persons tend to be politically strongly left-leaning and may be additionally but not exclusively categorized as vegetarians, vegans, eco-tarians, conservationists, environmentalists, neo-hippies, tree huggers, nature enthusiasts, etc.
Also used to describe establishments where alternative foods and products are sold, i.e. natural food stores.
In a tabletop game, a murderhobo is a player who murders NPCs indiscriminately. This is normally derogatory, referring to a player who totally ignores quests, dialog, backstory, trade, world building etc.
The term is most common with Dungeons and Dragons, but it can be applied to most RPGs where the player is allowed to kill most quest-giving NPCs and NPC traders. E.g. Elder Scrolls, Fallout, Divinity original sin.
DM: The sad little orphan girl tugs at Steve's trenchcoat to get his attention, and ask for help saving her pet dog from...
Steve: I'd like to roll a strength check against strangling the orphan.
Dave: I call dibs on the dog.
DM: You murderhobos disgust me.