1.
believer, follower (of a religion)
A person who follows or believes in a particular religion or faith.
仏教の信者が集まった。
Buddhist followers gathered.
この寺には全国から信者が訪れる。
Believers visit this temple from all over the country.
敬虔な信者として毎日祈りを捧げている。
As a devout believer, I offer prayers every day.
2.
devotee, die-hard fan
Used informally or sarcastically to describe someone who is an uncritical, zealous supporter of a person, brand, or idea.
彼はあのブランドの信者だ。
He's a devotee of that brand.
ネット上には熱狂的な信者がいる。
There are fanatical devotees online.
あの政治家の信者は何を言っても聞かない。
The devotees of that politician won't listen no matter what you say.
In sense 1, a neutral religious term. In sense 2, used informally (often pejoratively on the internet) to describe someone whose support is blind or cult-like. The informal usage is common in online discussions about brands, celebrities, and political figures.
COMMON COLLOCATIONS:
- 敬虔な信者 (devout believer)
- 熱心な信者 (earnest follower)
- 信者数 (number of followers/believers)