α. 1700s thinkembob, 1700s 1900s– thingambob, 1700s– thingabob, 1700s– thingembob, 1700s– thingumbob.
β. 1700s 1900s– thingamybob, 1800s– thingamabob, 1800s– thingamobob, 1800s– thingumabob, 1800s– thingumebob, 1800s– thingummybob, 1900s– thingamebob, 1900s– thingamibob, 1900s– thingammabob, 1900s– thingammibob, 1900s– thingammybob, 1900s– thingemmybob, 1900s– thingumibob, 1900s– thingummabob, 1900s– thingummebob, 1900s– thingummibob, 1900s– thingumybob, 1900s– thingymibob.
γ. English regional (Yorkshire) 1800s– thingemtibob, 1800s– thingumtibob.