Unfussy is an adjective that describes a person, thing or situation that is not complicated, demanding, or high-maintenance. Antonyms for the word unfussy include fussy, complicated, demanding, fastidious, and meticulous. Fussy refers to something that is overly particular, nitpicky, or difficult to please. Complicated is an antonym for unfussy because it suggests something that is unnecessarily intricate or difficult. Demanding means to require a lot of attention or energy. Fastidious suggests someone who is excessively particular and finicky. Finally, meticulous means showing great attention to detail and being overly concerned with accuracy. All of these antonyms for unfussy describe something that is the opposite of simplicity and ease.