Hypertonic comes from the Greek "hyper," meaning over, and "tonos," meaning stretching. In a hypertonic solution the total molar concentration of all dissolved solute particles is greater than that of another solution, or greater than the concentration in a cell.
If concentrations of dissolved solutes are greater outside the cell, the concentration of water outside is correspondingly lower. As a result, water inside the cell will flow outwards to attain equilibrium, causing the cell to shrink. As cells lose water, they lose the ability to function or divide. Hypertonic environments such as concentrated brines or syrups have been used since antiquity for food preservation because microbial cells that would otherwise cause spoilage are dehydrated in these very hypertonic environments and are unable to function.