Alasteir \a-las-teir, al(a)-steir\ as a boy's name is a variant of Alastair (Greek), and the meaning of Alasteir is "man's defender".

The baby name Alasteir sounds like Alaster, Alasdair, Alyster, Alystair, Allastir, Allaster, Alister, Alistair, Alester, Alaister, Alaistair, Alastor and Alistir. Other similar baby names are Alysdair, Allyster, Allystair, Allistir, Allister, Allistair, Alistar, Aleister, Alaisdair, Alistaire, Alisdair, Alstin, Alsten, Altair, Alltair and Alter.