1. (noun) a person who supplies information

• source

2. (noun) someone who sees an event and reports what happened

• witness
• witnesser

1. (noun) a person who supplies information

• betrayer
• blabber
• informer
• rat
• squealer
• leaker
• passive source
• whistle blower
• whistle-blower
• whistleblower

2. (noun) someone who sees an event and reports what happened

• attestant
• attester
• deponent
• deposer
• testifier

1. (noun) a person who supplies information

• communicator

2. (noun) someone who sees an event and reports what happened

• beholder
• observer
• perceiver
• percipient
• speaker
• talker
• utterer
• verbaliser
• verbalizer

1. (noun) a person who supplies information

• inform

2. (noun) someone who sees an event and reports what happened

• inform
• witness
• witness