Common Meanings
1
dì弟
younger brother; a male sibling younger than oneself
我的弟弟很喜欢踢足球。
My younger brother really likes playing football.
A younger male relative of the same generation, such as a younger male cousin (表弟 biǎodì for maternal side, 堂弟 tángdì for paternal side).
我的表弟今年考上了大学。
My younger cousin got into university this year.
A respectful term for a male peer who is younger or junior to oneself, like 'junior apprentice' or 'younger brother/pal'.
我的小师弟很聪明，学东西很快。
My junior apprentice is very smart and learns things quickly.
When pronounced 'dì', '弟' refers to a disciple or apprentice, often used by students addressing their teachers or others referring to a student in a master-apprentice relationship.
师傅，弟子已到。
Master, your disciple has arrived.
In archaic or literary contexts, '弟' can be used interchangeably with '第' to denote an ordinal number or sequence, meaning 'order' or 'the Xth'.
我们进入了比赛的弟二阶段。
We entered the second stage of the competition.
When pronounced 'dì', '弟' is typically found in the compound '次第' (cì dì), which means 'order', 'sequence', or 'one after another'. It conveys a sense of progression or arrangement, rather than marking an ordinal number directly like '第'.
请你按照文件上的次第，逐一核对信息。
Please check the information one by one according to the order on the document.
2
tì弟
Refers to fraternal duty, meaning respect and love towards one's older siblings, especially older brothers, often associated with filial piety.
他从小就懂得孝悌的道理，尊敬兄长。
From a young age, he understood the principles of filial piety and fraternal duty, respecting his older brothers.
3
tuí弟
When pronounced 'tuí', '弟' primarily appears in the phrase '弟靡' (tuí mí), meaning dejected, dispirited, or gentle and submissive.
他因长期失意，性格逐渐变得弟靡，不复往日雄心。
Due to prolonged disappointment, his character gradually became dispirited and subdued, no longer possessing his former ambition.