Nouns

(n)attendant, attender, tendersomeone who waits on or tends to or attends to the needs of another
(n)attendant, attender, attendee, meetera person who is present and participates in a meeting“he was a regular attender at department meetings”, “the gathering satisfied both organizers and attendees”
(n)accompaniment, concomitant, attendant, co-occurrencean event or situation that happens at the same time as or in connection with another

Adjectives

(s)attendantbeing present (at a meeting or event, etc.)“attendant members of the congregation”
(s)attendant, consequent, accompanying, concomitant, incidental, ensuant, resultant, sequent, collateraloccurring with or following as a consequence“an excessive growth of bureaucracy, with attendant problems”, “snags incidental to the changeover in management”, “attendant circumstances”, “the period of tension and consequent need for military preparedness”, “the ensuant response to his appeal”, “the resultant savings were considerable”, “collateral target damage from a bombing run”