In ancient Rome, an opening made at regular intervals in an aqueduct, for ventilation.

A secret agreement for illegal or fraudulent purposes.

A mixer designed to produce colloidal grout.

A grout which has artificially induced cohesiveness or ability to retain the dispersed solid particles in suspension.

Concrete whose aggregate is bound by colloidal grout.

A gelatinous substance so finely divided that it remains in suspension when dispersed in a liquid.

One which functions as a feeder from an area of limited traffic to a major street or highway.