Other forms: tinkering; tinkers; tinkered
When you tinker, you work casually or attempt to fix something, the way you might tinker with your brother's old bike or tinker with the website you're building for fun.
As a verb, tinker means to fix (or mess around with) just about anything. For example, your creative writing teacher might ask you to tinker with your most recent short story and add more specific, vivid details. As a noun, tinker refers to a person whose job involves traveling around and fixing things. It's an old-fashioned word, dating from the 13th century, when traveling tinsmith wasn't an uncommon occupation.