[n] small mackerel found nearly worldwide
[n] a traveling repairman who mends broken things (such as metal household utensils)
[n] (British) an itinerant Gypsy
[n] a person who enjoys fixing and experimenting with machines and their parts
[v] do random, unplanned work or activities or spend time idly; "The old lady is usually mucking about in her little house"
[v] work as a tinker or tinkerer