A person who is really into computers and electronics — knows them well, and usually enjoys them. It is a noun, and it is informal and friendly. "He's a bit of a techie" is the kind of thing you say about the friend who builds his own computer.

The feeling of the word depends on who says it. Among people who work with technology, calling yourself a techie is warm — it means you are one of us. From outside, it can be slightly teasing, suggesting someone who cares about machines more than about people. It is rarely nasty, though; if someone wants to be unkind they usually reach for a stronger word.

Two uses worth knowing. In offices, "the techies" often just means the IT department — the people you call when the system breaks — with no comment on personality at all. And in business writing, techie often means anyone working in the tech industry: "young techies moving to the city".

It is also used as an adjective in a loose way: "techie stuff", "a techie job". That use is casual and mostly spoken.

Spelling: "techie" is standard. "Techy" also exists but is best avoided — it collides with a different word, "techy" meaning bad-tempered, which is a variant of "tetchy" and has nothing to do with technology.