When was the name "Easter" first used for the celebration of the resurrection of Jesus? So what I'm trying to find out is who, and what religion, and where was this word "Easter" first used to describe the celebration of the resurrection of Jesus Christ?
There are a few ways to look at the origin of the word Easter:

That it comes from Eostre, an ancient Germanic goddess
That it comes from Eosturmonath, or &quot;month of beginnings&quot;
That it comes from Anglo-Saxon eastre, meaning dawn

Bede
The primary historical account of the origin of Easter comes from Bede's De temporum ratione (The Reckoning of Time, AD 725).  He presents the first view mentioned above, that the word comes from Eostre, the name of an ancient Germanic goddess.  He writes that this goddess had a month of celebration devoted to her, and that Anglo-Saxon Christians in early Medieval England appropriated that name for their celebration of the resurrection:

Eosturmonath has a name which is now translated &quot;Paschal month&quot;, and which was once called after a goddess of theirs named Eostre, in whose honour feasts were celebrated in that month.  Now they designate that Paschal season by her name, calling the joys of the new rite by the time-honored name of the old observance. (chapter 15)

Alternative interpretations
Bede's account seems straightforward, but many scholars doubt his analysis of the origin of the word Easter.  Ronald Hutton, in Stations of the Sun, accepts that a predecessor of the word was used in association with Christian resurrection festivals in the 8th and 9th centuries.  But he points to research that indicates less than perfect accuracy in Bede's explanations of this type, and summarizes:

It falls into that category of interpretations which Bede admitted to be his own, rather than generally agreed or proven fact.

Hutton also writes that the Anglo-Saxon eastre was associated with Indo-European words &quot;signifying dawn and also goddesses who personified that event.&quot;  Thus, he proposes two possible solutions that are &quot;equally valid,&quot; both of which ultimately point back to dawn:

That Bede's goddess Eostre was a Germanic dawn-deity who was indeed venerated by Anglo-Saxon pagans in the Spring
That Bede mistakenly associated Eosturmonath with a non-existent deity, or one simply associated with dawn and not directly with springtime, and that the word actually meant, simply, &quot;month of beginnings&quot; or &quot;month of openings,&quot; referring to the opening of buds in the Spring

Summary
The best we can say with some certainty is that Easter ultimately originates in Indo-European words meaning dawn.  The exact connection between the concept of dawn and the Easter celebration is less certain: perhaps simply an analogy between the dawning of a day and the arrival of springtime (and therefore Passover), or perhaps via the early Spring veneration of a dawn-goddess.
That said, scholars don't cast significant doubt on Bede's timeline: that by the 8th century, Christian celebrations of the resurrection were associated with a forerunner of the word Easter.