What is another word for plain-looking?
Pronunciation: [plˈe͡ɪnlˈʊkɪŋ] (IPA) 
When it comes to describing someone as plain-looking, there are a variety of synonyms that can be used to encompass the same idea. Some common synonyms include unremarkable, unassuming, simple, ordinary, average, nondescript, and unpretentious. These words all imply an appearance that is lacking in distinctive or striking features, and suggest that the person in question might blend in easily with a crowd. However, it's worth noting that while these words may describe someone's appearance, they don't necessarily convey anything about their personality, skills, or other attributes - so it's important to use them judiciously and not rely on them as the sole way of describing someone.
