To render sacred, to consecrate (Exodus 28:38; 29:1). This word is from the Saxon, and properly means "to make holy." The name of God is "hallowed", i.e., is reverenced as holy (Matthew 6:9).
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Hallow'". "Easton's Bible Dictionary".