答主

dázhǔ
  1. (Internet) one who answers a question on a Q&A site; answerer
  2. one who answers a question on a Q&A site; answerer

Wiktionary

Entry Composition

=1 答 dā bound form having the same meaning as the free word 答 dá, used in 答应 dāying, 答理 dāli etc
=1 答 dá
  1. to answer
  2. to reply
  3. to respond
=2 主 zhǔ
  1. owner
  2. master
  3. host
  4. individual or party concerned
  5. God
  6. Lord
  7. main
  8. to indicate or signify
  9. trump card (in card games)
=2 主 zhù
  1. Classifier for events.
  2. alternative form of 注 (zhù, “to pour into”)