attender

(noun) someone who listens attentively. Synonyms: hearer, listener, auditor.

(noun) someone who waits on or tends to or attends to the needs of another. Synonyms: attendant, tender.

(noun) a person who is present and participates in a meeting. Synonyms: attendant, attendee, meeter. Examples: "He was a regular attender at department meetings." "The gathering satisfied both organizers and attendees."