A person you think is strange — in how they dress, how they act, or what they say. It is informal and it is an insult, though a mild one.

A person you think is strange你覺得很奇怪的一個人 — in how they dress, how they act, or what they say不管是穿著、行為，還是說的話。It is informal and it is an insult這是口語，而且是一種罵人的話, though a mild one不過算是比較輕的。

Between friends who are joking, 'you weirdo' can be almost affectionate, the way you might laugh at a friend who eats ice cream with chopsticks. Said about a stranger, it is not affectionate at all: 'some weirdo was following me' means you felt uncomfortable, maybe a little frightened.

Between friends who are joking朋友之間開玩笑的時候, 'you weirdo' can be almost affectionate「you weirdo」幾乎可以是一種親暱, the way you might laugh at a friend who eats ice cream with chopsticks就像你笑一個用筷子吃冰淇淋的朋友那樣。Said about a stranger但用在陌生人身上, it is not affectionate at all就完全不是親暱了: 'some weirdo was following me'「some weirdo was following me」 means you felt uncomfortable, maybe a little frightened意思是你覺得不舒服，甚至有點害怕。

Because of this second use, be careful — calling someone a weirdo to their face, when you are not close, is rude and can hurt. There is a real cruelty in the word when it is aimed at someone who is different because of who they are rather than what they chose.

Because of this second use因為有這第二種用法, be careful要小心 — calling someone a weirdo to their face, when you are not close如果你們還不熟，當面叫別人weirdo, is rude and can hurt是很沒禮貌的，會傷到人。There is a real cruelty in the word當這個字帶著真正的殘忍 when it is aimed at someone who is different because of who they are rather than what they chose是針對一個人因為他本來的樣子而與眾不同（而不是他自己選擇的行為）時。

It is a countable noun: a weirdo, two weirdos. Plural is spelled with -s (weirdos), not -es.

It is a countable noun它是可數名詞: a weirdoa weirdo一個怪咖, two weirdostwo weirdos兩個怪咖。Plural is spelled with -s (weirdos)複數是加-s（weirdos）, not -es不是-es。

Some people also use it as an adjective, as in 'weirdo music', but that is much less common and sounds quite casual.

Some people also use it as an adjective有些人也會把它當形容詞用, as in 'weirdo music'像「weirdo music」, but that is much less common and sounds quite casual但這樣用比較少見，聽起來也相當隨性。

The word is fairly young — it appeared in American English around the 1950s — so it still sounds modern and spoken, not literary.

The word is fairly young這個字算相當年輕 — it appeared in American English around the 1950s大約在1950年代出現在美式英文裡 — so it still sounds modern and spoken, not literary所以它聽起來還是很現代、很口語，而不是文學用字。