What does Alastair mean?
Alastair \a-las-tair, al(a)-stair\ as a boys' name (also used as girls' name Alastair) is of Scottish and Greek origin, and the meaning of Alastair is "man's defender". Scottish variant of Alistair, from Alexander. Most of the variants are different phonetic spellings of the name. TV commentator Alistair Cooke; actor Alistair Sim.
Alastair has 26 variants: Al▼, Alaisdair, Alaistair, Alaister, Alasdair, Alasteir, Alaster, Alastor, Aleister, Alester, Alistair, Alistar, Alister, Allaistar, Allaster, Allastir, Allistair, Allister, Allistir, Allysdair, Allystair, Allyster, Alysdair, Alysdare, Alystair and Alyster.
Alastair is an uncommonly occurring first name for men. Alastair is also an uncommon surname for all people. (2000 U.S. Census)
Displayed below is a comparison of the usage of Alastair and associated names. Prominent alternative forms of Alastair (#unlisted) are Alexander (#8 in 2014), Alistair and Al. Adoption of these boy names reached its highest during 1880-1889 (usage of 0.511%) and is now much less (usage 0.3307%, down 35.3%), with the version Al becoming less in vogue. Alexander (#8) is the most contemporarily stylish boy name here, with this name having a resurgence in usage. (Top 1000 Birth Names Records, 2014)