Proper noun
A male given name transferred from the surname.
A surname from Irish.
Source: en.wiktionary.orgThat of all the floures in the mede, Thanne love I most these floures white and rede, Suche as men callen daysyes in her toune. Geoffrey Chaucer
Although, if that happened, viewers would miss the chemistry between Hanna and Callen, which is a big part of the enjoyment of the show. Source: Internet
Despite the anxiety and uncertainty, Dr. Callen isn't discouraging people from getting pregnant. Source: Internet
Callen plays the violin and Jody who plays the guitar. Source: Internet
Callen and his team tracked Darius from the airport. Source: Internet
' (≈ Callen, pp. 189–190) An even stronger assertion is that It is impossible by any procedure to reduce the temperature of a system to zero in a finite number of operations. Source: Internet