Kiernan is an Irish surname turned given name, derived from the Gaelic 'Ciarán', which means 'little dark one'. It gained popularity as a first name during the late 20th century. The name Kiernan consists of two elements: 'ciar' meaning 'dark', and 'an' meaning 'little'. This moniker thus suggests a person who is small in stature but perhaps has a strong, profound presence. In Irish mythology, Ciarán of Saigir was a renowned saint known for his wisdom and eloquence, which may have contributed to the enduring appeal of this name.
The name Kiernan experienced significant fluctuations in popularity over the years, with a notable surge starting around 1993 and peaking between 1999 and 2003. However, it seems to have declined steadily since then.