A gadget, gizmo or doodad was a slang term for an electronic tool or piece of technology.
In 2263 of the alternate reality, Leonard McCoy wondered if the swarm drones really attacked USS Enterprise for a doodad (the Abronath) that the Teenaxi had rejected. Spock replied, "It is unwise to trivialize that which one simply does not understand, Doctor. We can safely assume it is more important than a doodad." (Star Trek Beyond)
(TOS: "Space Seed")
(TOS: "The Ultimate Computer")
(TNG: "Time's Arrow, Part II")
In 2368, Robin Lefler mistakenly referred to the Ktarian game as a "Risian gadget", as William Riker had brought it from Risa. (TNG: "The Game")
(DS9: "Little Green Men")
(DS9: "Future's End, Part II")
(DS9: "The Begotten")
(LD: "Crisis Point 2: Paradoxus")
(LD: "Dos Cerritos")