Admission
An admission is a party's statement acknowledging that a certain statement or fact asserted against that party is true. In certain circumstances an admission can be made by silence. For example, silence after another party's assertion of a fact, would typically elicit an acknowledgment of the asserted fact.
Admission by a party-opponent: an out-of-court statement by a party that is against the party's interest and that is admissible against the party, because admissions by party-opponents are not considered hearsay.