(mining, historical) A boy employed to assist the barrowman out of a dip place.

plural of helper-up

A virus used to assist in the replication of viral vectors

plural of helper grade

(rail transport, US) A railroad gradient where helper locomotives are required to assist the train locomotives.

plural of helper T cell

(immunology) A subtype of T cell that helps the activity of other immune cells by releasing cytokines, playing an important role in the adaptive immune system.

(immunology) A helper T cell.

plural of T helper cell

(slang, euphemistic) A tranquilizer taken to reduce anxiety; meprobamate, diazepam.