noun
thumb tribe; thumb generation
Coined term for people who constantly type on their phones with their thumbs, especially for texting or social media. Often used in media and social commentary.
最近の若者はみんな親指族だと言われる。
It's said that all young people these days are part of the thumb tribe.
電車の中は親指族
The train was full of people typing away on their phones.
noun
pachinko addict
Slang extension: a person addicted to pachinko, from the repetitive thumb motion used to operate the machine. Less common than the phone-typing sense.
彼は親指族で、毎日パチンコ屋に通っている。
He's a pachinko addict and goes to the parlor every day.