taboo

Belgrade (the capital city of Serbia)

(mineralogy) opal, a mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity

diesel

member, a person who is in a group / participant, attendee at an event / (programming) member in object-oriented programming / (Internet slang) suspect in a crime

Madrid (a city and municipality of the Community of Madrid, Spain; capital city of Spain) / Madrid, Community of Madrid (an autonomous community of Spain)

(music) fugue

(fiction, Internet) troll

(electronics) Synonym of 電池 (denchi, “battery”) (device storing electricity) / (baseball, softball) a battery (the catcher and the pitcher together)

railgun (electromagnetic gun)