bi-
bi- — prefix
1. a word beginning that means 'two times in a period' or 'once in every two period
a word beginning that means 'two times in a period' or 'once in every two periods'. For example, a biweekly magazine comes out every two weeks, while biannual check-ups happen twice a year.
The town publishes a biweekly paper that arrives every other Thursday morning.
biweekly — every two weeks
Ingrid goes for biannual dental check-ups, once in March and once in September.
biannual — twice a year
The biennial art show runs every two years, drawing visitors from across the region.
Kwame set up a bimonthly standing order at the bank for the first and fifteenth of each month.
用法筆記
This prefix can cause confusion because the same word sometimes means 'twice per period' and sometimes 'every two periods'. In careful writing, use 'semi-' for 'twice per' (semiweekly = twice a week) and 'bi-' for 'every two' (biweekly = every two weeks), though not everyone follows this rule.
常見錯誤
2. a word beginning that means 'having two of something' or 'involving both sides'.
a word beginning that means 'having two of something' or 'involving both sides'. It appears in words like bilingual (using two languages) and bilateral (affecting two sides equally).
Dr. Okonkwo hired a bilingual receptionist who speaks both English and Igbo fluently.
bilingual — speaking two languages
The two countries reached a bilateral trade deal after six months of difficult talks.
bilateral — involving two sides
Santiago bought bifocal glasses so he could read a book and watch the television clearly.
A bipedal robot walked steadily across the workshop floor on two jointed legs.
The bipartisan committee included members from both major parties working together on the bill.
用法筆記
This sense of 'bi-' combines freely with roots to form adjectives and nouns describing things with two parts, sides, or members. It is different from sense 1 (time-related) — here there is no 'per period' meaning, just the idea of twoness.
常見錯誤
bi- — adjective
1. a short everyday word meaning bisexual: describing a person who feels romantic o
a short everyday word meaning bisexual: describing a person who feels romantic or physical attraction to both their own gender and other genders.
Hana told her closest friends she is bi after dating a woman and then a man.
is bi — adjective after 'to be'
The youth centre started a new support group for bi teenagers and their families.
bi teenagers — adjective before a noun
Deepak found it hard to talk about being bi in the small village where he grew up.
A bi character in the television drama helped many viewers feel seen and understood.
用法筆記
Used both before nouns ('bi community') and after verbs like 'be' and 'identify as' ('she is bi'). The full word 'bisexual' is more common in formal writing, while 'bi' is the typical choice in everyday talk and within LGBTQ+ spaces.
常見錯誤
bi- — noun
1. an informal word for a person who feels romantic or physical attraction to peopl
an informal word for a person who feels romantic or physical attraction to people of more than one gender; the noun form that matches the adjective 'bisexual'.
Zainab came out as a bi to her parents during a quiet dinner at home.
a bi — noun phrase for a bisexual person
The magazine interviewed several bi about their experiences with dating and relationships.
Matteo wrote an honest essay about growing up as a bi in a traditional Italian family.
A local bi spoke at the school assembly about the importance of being true to yourself.
- bisexual
can be used as a noun too ('he is a bisexual'); more formal and widely recognised than 'bi'
- bisexual person
the clearest, most explicit term; used in formal contexts and surveys
用法筆記
This is the countable noun form ('a bi', 'several bi'). It is common in casual speech and LGBTQ+ community contexts. In more formal situations, 'bisexual person' or just 'bisexual' as a noun is the standard choice.