doubter

noun

1. someone who habitually doubts accepted beliefs

   Synonyms

   • skeptic, sceptic

   Less specific

   • intellectual, intellect

   More specific

   • doubting Thomas, pessimist

2. someone who is doubtful or noncommittal about something

   Synonyms

   • agnostic

   Less specific

   • person, individual, someone, somebody, mortal, soul