To make a pattern on cloth by tying string tightly round parts of it and then putting the whole thing in dye — coloured liquid. Where the string squeezes the cloth, the colour cannot get in, so those parts stay pale, and you get soft rings or spirals of colour when you untie it. It is a simple thing to do at home or in a school art class, which is why the word is common. It works as a verb ("we tie-dyed our T-shirts"), as a noun for the technique or the cloth ("she wears a lot of tie-dye"), and as an adjective, usually written tie-dyed before the noun ("a tie-dyed shirt"). The style is strongly linked in people's minds to the hippies of the 1960s, so calling clothes tie-dye can quietly suggest relaxed, arty, a bit unserious — though it comes back into fashion every few years and plenty of expensive brands sell it.