These terms occasionally come up on the discord but I think they are useful to help figure out what people want in miniatures games. I don't know the origin of some of these.

30 days

A method to getting hobby things done or to engross yourself in a topic. You select a single topic and focus all of your hobby efforts on only that for 30 days. If your focus is "Stalingrad" for your ww2 collection you only buy, build, paint and play games related to Stalingrad for 30 days. Existing social commitments are exempt so you don't have to cancel your weekend Magic the Gathering game.

In "Epic 30 days" extend this to music, film and books as much as possible as well. 

Grog

Short for Grognard. An old school wargamer. Is often a bit stuffy and set in their ways but also tends to be less motivated by commercial hype. Note that grog is a state of mind and not actually correlated to age. 

Rank and flank

Typically a medieval or fantasy game where troops are arranged in ranks and files and move as blocks. Often associated with individual figure removal but does not require it. Examples: Warhammer Fantasy Battles. 

Skirmish

Nobody agrees on what this means. To me a game is a skirmish game if a single figure represents a single soldier and has at least semi-autonomous actions (moving and firing individually, even if it is part of a squad f.x.). Typically 30 or less figures. Examples: Chain of Command or Warhammer 40.000.

A derivative is Big Skirmish which is a skirmish or semi-skirmish game with 40+ figures. 

Social solo

Playing solo miniatures games but sharing them online, whether on a forum, social media network or Discord server. Allows social interaction around the games with people commenting on each others games, storylines and figures/terrain.

Out of the box

A game where by reading along in the book, it will produce forces and a ready to play scenario for you. Contrasted with games where you have to create your own scenarios or build armies. 

Originally devised to describe my own Five Parsecs From Home.

Warband

A game where each player has only a handful of figures, but they are carried over between battles with some sort of progression system. Examples include Necromunda, Gangs of Mega-City One or my own Five Leagues From the Borderlands.