1.Definition: certain to occur; destined or inevitable
"He was certain to fail", "His fate is certain", "In this life nothing is certain but death and taxes", "He faced certain death"
2.Definition: definite but not specified or identified
"Set aside a certain sum each week", "To a certain degree", "Certain breeds do not make good pets", "Certain members have not paid their dues", "A certain popular teacher", "A certain Mrs. Jones"
3.Definition: established beyond doubt or question; definitely known
"What is certain is that every effect must have a cause", "It is certain that they were on the bus", "His fate is certain", "The date for the invasion is certain"
4.Definition: established irrevocably
5.Definition: exercising or taking care great enough to bring assurance
"Be certain to disconnect the iron when you are through"
6.Definition: having or feeling no doubt or uncertainty; confident and assured
"Felt certain of success", "Was sure (or certain) she had seen it"
7.Definition: reliable in operation or effect
"A quick and certain remedy"