Alasdair \a-las-dair, al(a)-sdair\ as a boy's name (also used as girl's name Alasdair), is pronounced AL-as-dare. It is of Greek origin, and the meaning of Alasdair is "man's defender". Scottish Gaelic form of Alexander, often anglicized as Alistair.

For more information, see also the related name Alastair.

Baby names that sound like Alasdair are Alysdair, Alaisdair and Alisdair. Other similar baby names are Alystair, Allysdair, Alaistair and Alasteir.