Declan, the Anglicized form of the Irish name Deaglán, is believed to be derived from the Irish elements deagh, meaning "good," and lán, meaning "full." Therefore, it could translate to "full of goodness." It first appeared in the Social Security Administration's top 1,000 for boy names in 1998, one year after the release of "The Jackal," which featured a character named Declan Mulqueen, played by Richard Gere. It received another boost in 2011 when it entered the top-200 for the first time, one year after the release of "Leap Year" starring Matthew Goode as Declan O'Callaghan. It has now been a top-150 boy's name every year since 2012 and it's the name country singer Harper Grae gave her daughter Declan Monroe, born in 2021.
