Act in an official capacity in a ceremony or religious ritual, such as a wedding.

Roget 631: subserve, minister, mediate, intervene; be instrumental etc. adj.; pander to; officiate; tend.   

Roget 998: perform service [ritual actions of clergy], do duty, minister, officiate, baptize, dip, sprinkle; anoint, confirm, lay hands on; give the sacrament, administer the sacrament; administer extreme unction; hear confession, administer holy penance, shrive; excommunicate, ban with bell book and candle.    [ritual actions of believers] attend services, attend mass, go to mass, hear mass; take the sacrament, receive the sacrament, receive communion, attend the sacrament, partake of the sacrament, partake of communion; communicate; receive extreme unction; confess, go to confession, receive penance; anele^†.    [teaching functions of clergy] preach, sermonize, predicate, lecture.    ... show more

Roget 692: transact [cause to occur], execute; despatch, dispatch; proceed with, discharge; carry on, carry through, carry out, carry into effect, put into effect; work out; go through, get through; enact; put into practice; do etc. 680; officiate etc. 625.    bear oneself, behave oneself, comport oneself, demean oneself, carry oneself, conduct oneself, acquit oneself.    run a race, lead a life, play a game; take a course, adopt a course; steer one's course, shape one's course; play one's paint, play one's cards, shift for oneself; paddle one's own canoe; bail one's own boat.    conduct; manage, supervise etc. (direct) 693.    participate etc. 680.    deal with, have to do with; treat, handle a case; take steps, take measures.    ... show more

Roget 625: pass one's time in, employ one's time in, spend one's time in; employ oneself in, employ oneself upon; occupy oneself with, concern oneself with; make it one's business etc. n.; undertake etc. 676; enter a profession; betake oneself to, turn one's hand to; have to do with etc. (do) 680.    office, place, post, chargeship^†, incumbency, living; situation, berth, employ; service etc. (servitude) 749; engagement; undertaking etc. 676.    drive a trade; carry on a trade, do a trade, transact a trade, carry on business, do business, transact business etc. n.; keep a shop; ply one's task, ply one's trade; labor in one's vocation; pursue the even tenor of one's way; attend to business, attend to one's work.    officiate, serve, act; act one's part, play one's part; do duty; serve the office of, discharge the office of, perform the office of, perform the duties of, perform the functions of; hold an office, fill an office, fill a place, fill a situation; hold a portfolio, hold a place, hold a situation.    be about, be doing, be engaged in, be employed in, be occupied with, be at work on; have one's hands in, have in hand; have on one's hands, have on one's shoulders; bear the burden; have one's hands full etc. (activity) 682.    be in the hands of, be on the stocks, be on the anvil; pass through one's hands.    ... show more

Roget 680: do, perform, execute; achieve etc. (complete) 729; transact, enact; commit, perpetrate, inflict; exercise, prosecute, carry on, work, practice, play.    employ oneself, ply one's task; officiate, have in hand etc. (business) 625; labor etc. 686; be at work; pursue a course; shape one's course etc. (conduct) 692.    act, operate; take action, take steps; strike a blow, lift a finger, stretch forth one's hand; take in hand etc. (undertake) 676; put oneself in motion; put in practice; carry into execution etc. (complete) 729; act upon.    be an actor etc. 690; take a part in, act a part in, play a part in, perform a part in; participate in; have a hand in, have a finger in the pie; have to do with; be a party to, be a participator in; bear a hand, lend a hand; pull an oar, run in a race; mix oneself up with etc. (meddle) 682.    be in action; come into operation etc. (power at work) 170.    ... show more

Perform duties attached to a particular office or place or function:
— His wife officiated as his private secretary.

synonym: function.