A bricklayer was an artisan who specialized in the trade of masonry work, specifically building with brick and mortar, but who also worked with concrete and stone.
When Captain Kirk ordered Doctor McCoy to assist the injured silicon-based Mother Horta in 2267 – something which was outside of the doctor's area of expertise – McCoy exclaimed, "I'm a doctor, not a bricklayer." (TOS: "The Devil in the Dark")