Encomium, eulogy, panegyric, tribute, citation denote a more or less formal and public expression of praise.
Encomium implies enthusiasm or warmth in praising a thing or more often a person.
Eulogy implies a more studied form than encomium; as a rule it applies to a speech (or writing) extolling the virtues and the services of a person; the term is especially and specifically applied to a funeral oration or sermon of this character.
Panegyric carries a far stronger implication of elaborate, high-flown, often poetical or rhetorical compliment than either of the preceding terms but it does not now emphasize publicity as much as it once did.
Tribute applies not only to spoken or written praise but to any act or situation which can be construed as taking its place.
Citation is used in designating either the formal eulogy accompanying the awarding of an honor (as an honorary degree) or the specific mention of a person in military service in an order or dispatch.