Thingumajig used in a sentence

noun

something unspecified whose name is either forgotten or not known; "she eased the ball-shaped doodad back into its socket"; "there may be some great new gizmo around the corner that you will want to use"

See also: doodad doohickey doojigger gimmick gizmo gismo gubbins thingamabob thingumabob thingmabob thingamajig