Atar
From Tolkien Gateway
atar (pl. atari) is a Quenya word meaning father.
Etymology
Possibly PQ *ataro from root ATA[1]
Other forms
See also
Cognates
Inspiration
Atar can be compared to Greek/Latin pater.
In Gothic and Celtic branches the Indoeuropean initial p- was lost thence we have forms similar to atar, like Irish athair (from Proto-Celtic *ɸatīr) and Gothic atta.
Note also Turkish atto